Name: ______________________ Date: _________ ID: A

1

Physics 201 Midterm Exam 2

Information and Instructions

Student ID Number: ______________________

Section Number: ______________________

TA Name: ______________________

Please fill in all the information above.

Please write and bubble your Name and Student Id number on your scatron. Also fill in your section number under speacial codes. Finally question 1 asks you to fill in your teset ID code which is necessary to correctly grade your exam.

The exam has 20 questions (questions 2-21) and you have 1 hour and 15 mintues to complete the exam.

Please use 9.80 m/s^2 for the acceleration of gravity on the Earth.

.

____ 1. Please fill in your test ID codea. A c. Cb. B d. D

Name: ______________________ ID: A

2

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 2. An airplane travels 80.0 m/s as it makes a horizontal circular turn which has a 0.80-km radius. What is the magnitude of the resultant force on the 75-kg pilot of this airplane?a. 0.60 kN forward in the direction the plane’s velocity at any momentb. 600 kN forward in the direction the plane’s velocity at any momentc. 0.74 kN upwardd. 0.60 kN inward toward the center of the circlee. 0.95 kN upward and inward toward the center of the circle

____ 3. A split highway has a number of lanes for traffic. For traffic going in one direction, the radius for the inside of the curve is half the radius for the outside. One car, car A, travels on the inside while another car of equal mass, car B, travels at equal speed on the outside of the curve. Which statement about resultant forces on the cars is correct?a. The force on A is half the force on B.b. The force on B is half the force on A.c. The force on A is four times the force on B.d. The force on B is four times the force on A.e. There is no net resultant force on either as long as they stay on the road while

turning.

____ 4. The coefficient of static friction for the tires of a race car is 0.950 and the coefficient of kinetic friction

is 0.800. The car is on a level circular track of 50.0 m radius on a planet where g = 2.45 ms2

compared to

Earth's g = 9.80 ms2

. If the car is to be able to travel at the same maximum speed without slipping on the

planet as on Earth, the radius of the track on the planet must be ____ times as large as the radius of the track on Earth.a. 0.250b. 0.500c. 1.00d. 2.00e. 4.00

____ 5. A skydiver of 75 kg mass has a terminal velocity of 60.0 m/s. At what speed is the resistive force on the skydiver half that when at terminal speed?a. 15 m/sb. 49 m/sc. 30 m/sd. 42 m/se. 36 m/s

Name: ______________________ ID: A

3

____ 6. If a dense 20.0-kg object is falling in air at half its terminal velocity, what is the drag force on the object at this moment?a. 24.5 Nb. 49.0 Nc. 69.3 Nd. 98.0 Ne. 139 N

____ 7. A 2.0-kg projectile moves from its initial position to a point that is displaced 20.0 m horizontally and 15 m above its initial position. How much work is done by the gravitational force on the projectile?a. +0.29 kJb. −0.29 kJc. +30 Jd. −30 Je. −50 J

____ 8. A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.50 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B?

a. 2.8 Jb. 1.0 Jc. 2.2 Jd. 1.6 Je. 3.2 J

Name: ______________________ ID: A

4

____ 9. A 10.0-kg block on a horizontal frictionless surface is attached to a light spring (force constant = 0.80 kN/m). The block is initially at rest at its equilibrium position when a force (magnitude P = 80.0 N) acting parallel to the surface is applied to the block, as shown. What is the speed of the block when it is 13 cm from its equilibrium position?

a. 0.85 m/sb. 0.89 m/sc. 0.77 m/sd. 0.64 m/se. 0.52 m/s

____ 10. When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction mk, then dragged back along the same path to its original position, the work done by friction isa. 0.b. −mkmgd.c. +mkmgd.d. −2mkmgd.e. +2mkmgd.

____ 11. Two clowns are launched horizontally from the same spring-loaded circus cannon with the spring compressed the same distance each time. Clown A has a 40-kg mass; clown B a 60-kg mass. The relation between their speeds at the instant of launch is

a. vA =32

vB.

b. vA =32

vB.

c. vA = vB.

d. vB =32

vA.

e. vB =32

vA.

Name: ______________________ ID: A

5

____ 12. A spring (k = 600.0 N/m) is placed in a vertical position with its lower end supported by a horizontal surface. The upper end is depressed 20.0 cm, and a 4.0-kg block is placed on top of the depressed spring, but not attached to the spring. The system is then released from rest. How far above the point of release will the block rise?a. 27 cmb. 36 cmc. 41 cmd. 31 cme. 20 cm

____ 13. A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70.0-kg athlete were to bicycle to the summit of a 0.50-km high mountain while expending power at this rate, she would reach the summit in ____ seconds.a. 1b. 460c. 500d. 1 000e. 35 000

____ 14. As an object moves from point A to point B only two forces act on it: one force is nonconservative and does −30 J of work, the other force is conservative and does +50 J of work. Between A and B,a. the kinetic energy of object increases, mechanical energy decreases.b. the kinetic energy of object decreases, mechanical energy decreases.c. the kinetic energy of object decreases, mechanical energy increases.d. the kinetic energy of object increases, mechanical energy increases.e. None of the above.

____ 15. A 3.0-kg object moving in the positive x direction has a one-dimensional elastic collision with a 5.0-kg object initially at rest. After the collision the 5.0-kg object has a velocity of 6.0 m/s in the positive x direction. What was the initial speed of the 3.0 kg object?a. 6.0 m/sb. 7.0 m/sc. 4.5 m/sd. 8.0 m/se. 5.5 m/s

____ 16. A ball of mass mB is released from rest and acquires velocity of magnitude vB before hitting the ground. The ratio of the kinetic energy the Earth acquires to the kinetic energy the ball acquires isa. 0.

b.m B

m E

Ê

Ë

ÁÁÁÁÁÁÁÁÁÁ

ˆ

¯

˜̃̃˜̃̃˜̃̃˜

2

.

c.m B

m E

.

d. 1

e.m E

m B

.

Name: ______________________ ID: A

6

____ 17. A 3.0-kg mass moving in the positive x direction with a speed of 10 m/s collides with a 6.0-kg mass initially at rest. After the collision, the speed of the 3.0-kg mass is 8.0 m/s, and its velocity vector makes an angle of 35° with the positive x axis. What is the magnitude of the velocity of the 6.0-kg mass after the collision?a. 2.2 m/sb. 2.9 m/sc. 4.2 m/sd. 3.5 m/se. 4.7 m/s

____ 18. A 4.2-kg object, initially at rest, "explodes" into three objects of equal mass. Two of these are determined to have velocities of equal magnitudes (5.0 m/s) with directions that differ by 90.0°. How much kinetic energy was released in the explosion?a. 70 Jb. 53 Jc. 60 Jd. 64 Je. 35 J

____ 19. Three particles are placed in the xy plane. A 40-g particle is located at (3, 4) m, and a 50-g particle is positioned at (−2, −6) m. Where must a 20-g particle be placed so that the center of mass of this three-particle system is located at the origin?a. (−1, −3) mb. (−1, 2) mc. (−1, 12) md. (−1, 7) me. (−1, 3) m

____ 20. Car A rear ends Car B, which has twice the mass of A, on an icy road at a speed low enough so that the collision is essentially elastic. Car B is stopped at a light when it is struck. Car A has mass m and speed v before the collision. After the collisiona. each car has half the momentum.b. car A stops and car B has momentum mv.c. car A stops and car B has momentum 2mv.d. the momentum of car B is four times as great in magnitude as that of car A.e. each car has half of the kinetic energy.

____ 21. Consider a physical situation like that in lab M-5, Projectile Motion. If the projectile has a mass of 0.010 kg is moving at 90.0 m/s, and is caught by a catcher of mass 0.50 kg, how far does the catcher rise?a. 0.16b. 0.51c. 0.32d. 0.64e. 0.080

ID: A

1

Physics 201 Midterm Exam 2Answer Section

MULTIPLE RESPONSE

1. ANS: A, B, C, D PTS: 1

MULTIPLE CHOICE

2. ANS: D PTS: 2 DIF: Average 3. ANS: B PTS: 1 DIF: Easy 4. ANS: E PTS: 3 DIF: Challenging 5. ANS: D PTS: 2 DIF: Average 6. ANS: B PTS: 2 DIF: Average 7. ANS: B PTS: 2 DIF: Average 8. ANS: C PTS: 2 DIF: Average 9. ANS: A PTS: 2 DIF: Average 10. ANS: D PTS: 1 DIF: Easy 11. ANS: B PTS: 1 DIF: Easy 12. ANS: D PTS: 2 DIF: Average 13. ANS: B PTS: 2 DIF: Average 14. ANS: A PTS: 1 DIF: Easy 15. ANS: D PTS: 2 DIF: Average 16. ANS: C PTS: 2 DIF: Average 17. ANS: B PTS: 3 DIF: Challenging 18. ANS: A PTS: 2 DIF: Average 19. ANS: D PTS: 2 DIF: Average 20. ANS: D PTS: 3 DIF: Challenging 21. ANS: A PTS: 1

Name: ______________________ Date: _________ ID: B

1

Physics 201 Midterm Exam 2

Information and Instructions

Student ID Number: ______________________

Section Number: ______________________

TA Name: ______________________

Please fill in all the information above.

Please write and bubble your Name and Student Id number on your scatron. Also fill in your section number under speacial codes. Finally question 1 asks you to fill in your teset ID code which is necessary to correctly grade your exam.

The exam has 20 questions (questions 2-21) and you have 1 hour and 15 mintues to complete the exam.

Please use 9.80 m/s^2 for the acceleration of gravity on the Earth.

.

____ 1. Please fill in your test ID codea. A c. Cb. B d. D

Name: ______________________ ID: B

2

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 2. An airplane travels 80.0 m/s as it makes a horizontal circular turn which has a 0.80-km radius. What is the magnitude of the resultant force on the 75-kg pilot of this airplane?a. 0.60 kN forward in the direction the plane’s velocity at any momentb. 0.95 kN upward and inward toward the center of the circlec. 600 kN forward in the direction the plane’s velocity at any momentd. 0.74 kN upwarde. 0.60 kN inward toward the center of the circle

____ 3. A split highway has a number of lanes for traffic. For traffic going in one direction, the radius for the inside of the curve is half the radius for the outside. One car, car A, travels on the inside while another car of equal mass, car B, travels at equal speed on the outside of the curve. Which statement about resultant forces on the cars is correct?a. The force on A is four times the force on B.b. There is no net resultant force on either as long as they stay on the road while

turning.c. The force on B is four times the force on A.d. The force on B is half the force on A.e. The force on A is half the force on B.

____ 4. The coefficient of static friction for the tires of a race car is 0.950 and the coefficient of kinetic friction

is 0.800. The car is on a level circular track of 50.0 m radius on a planet where g = 2.45 ms2

compared to

Earth's g = 9.80 ms2

. If the car is to be able to travel at the same maximum speed without slipping on the

planet as on Earth, the radius of the track on the planet must be ____ times as large as the radius of the track on Earth.a. 1.00b. 0.500c. 2.00d. 0.250e. 4.00

____ 5. A skydiver of 75 kg mass has a terminal velocity of 60.0 m/s. At what speed is the resistive force on the skydiver half that when at terminal speed?a. 15 m/sb. 30 m/sc. 36 m/sd. 42 m/se. 49 m/s

Name: ______________________ ID: B

3

____ 6. If a dense 20.0-kg object is falling in air at half its terminal velocity, what is the drag force on the object at this moment?a. 69.3 Nb. 98.0 Nc. 139 Nd. 24.5 Ne. 49.0 N

____ 7. A 2.0-kg projectile moves from its initial position to a point that is displaced 20.0 m horizontally and 15 m above its initial position. How much work is done by the gravitational force on the projectile?a. +30 Jb. −0.29 kJc. −30 Jd. −50 Je. +0.29 kJ

____ 8. A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.50 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B?

a. 1.0 Jb. 3.2 Jc. 1.6 Jd. 2.8 Je. 2.2 J

Name: ______________________ ID: B

4

____ 9. A 10.0-kg block on a horizontal frictionless surface is attached to a light spring (force constant = 0.80 kN/m). The block is initially at rest at its equilibrium position when a force (magnitude P = 80.0 N) acting parallel to the surface is applied to the block, as shown. What is the speed of the block when it is 13 cm from its equilibrium position?

a. 0.52 m/sb. 0.64 m/sc. 0.77 m/sd. 0.89 m/se. 0.85 m/s

____ 10. When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction mk, then dragged back along the same path to its original position, the work done by friction isa. +mkmgd.b. −2mkmgd.c. +2mkmgd.d. −mkmgd.e. 0.

____ 11. Two clowns are launched horizontally from the same spring-loaded circus cannon with the spring compressed the same distance each time. Clown A has a 40-kg mass; clown B a 60-kg mass. The relation between their speeds at the instant of launch isa. vA = vB.

b. vB =32

vA.

c. vB =32

vA.

d. vA =32

vB.

e. vA =32

vB.

Name: ______________________ ID: B

5

____ 12. A spring (k = 600.0 N/m) is placed in a vertical position with its lower end supported by a horizontal surface. The upper end is depressed 20.0 cm, and a 4.0-kg block is placed on top of the depressed spring, but not attached to the spring. The system is then released from rest. How far above the point of release will the block rise?a. 31 cmb. 36 cmc. 27 cmd. 20 cme. 41 cm

____ 13. A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70.0-kg athlete were to bicycle to the summit of a 0.50-km high mountain while expending power at this rate, she would reach the summit in ____ seconds.a. 460b. 35 000c. 500d. 1e. 1 000

____ 14. As an object moves from point A to point B only two forces act on it: one force is nonconservative and does −30 J of work, the other force is conservative and does +50 J of work. Between A and B,a. the kinetic energy of object decreases, mechanical energy increases.b. the kinetic energy of object increases, mechanical energy decreases.c. the kinetic energy of object decreases, mechanical energy decreases.d. the kinetic energy of object increases, mechanical energy increases.e. None of the above.

____ 15. A 3.0-kg object moving in the positive x direction has a one-dimensional elastic collision with a 5.0-kg object initially at rest. After the collision the 5.0-kg object has a velocity of 6.0 m/s in the positive x direction. What was the initial speed of the 3.0 kg object?a. 6.0 m/sb. 8.0 m/sc. 4.5 m/sd. 7.0 m/se. 5.5 m/s

____ 16. A ball of mass mB is released from rest and acquires velocity of magnitude vB before hitting the ground. The ratio of the kinetic energy the Earth acquires to the kinetic energy the ball acquires is

a.m E

m B

.

b. 1

c.m B

m E

Ê

Ë

ÁÁÁÁÁÁÁÁÁÁ

ˆ

¯

˜̃̃˜̃̃˜̃̃˜

2

.

d. 0.

e.m B

m E

.

Name: ______________________ ID: B

6

____ 17. A 3.0-kg mass moving in the positive x direction with a speed of 10 m/s collides with a 6.0-kg mass initially at rest. After the collision, the speed of the 3.0-kg mass is 8.0 m/s, and its velocity vector makes an angle of 35° with the positive x axis. What is the magnitude of the velocity of the 6.0-kg mass after the collision?a. 4.2 m/sb. 4.7 m/sc. 3.5 m/sd. 2.9 m/se. 2.2 m/s

____ 18. A 4.2-kg object, initially at rest, "explodes" into three objects of equal mass. Two of these are determined to have velocities of equal magnitudes (5.0 m/s) with directions that differ by 90.0°. How much kinetic energy was released in the explosion?a. 70 Jb. 35 Jc. 64 Jd. 53 Je. 60 J

____ 19. Three particles are placed in the xy plane. A 40-g particle is located at (3, 4) m, and a 50-g particle is positioned at (−2, −6) m. Where must a 20-g particle be placed so that the center of mass of this three-particle system is located at the origin?a. (−1, 7) mb. (−1, 12) mc. (−1, −3) md. (−1, 3) me. (−1, 2) m

____ 20. Car A rear ends Car B, which has twice the mass of A, on an icy road at a speed low enough so that the collision is essentially elastic. Car B is stopped at a light when it is struck. Car A has mass m and speed v before the collision. After the collisiona. car A stops and car B has momentum 2mv.b. each car has half the momentum.c. the momentum of car B is four times as great in magnitude as that of car A.d. car A stops and car B has momentum mv.e. each car has half of the kinetic energy.

____ 21. Consider a physical situation like that in lab M-5, Projectile Motion. If the projectile has a mass of 0.010 kg is moving at 90.0 m/s, and is caught by a catcher of mass 0.50 kg, how far does the catcher rise?a. 0.51b. 0.080c. 0.32d. 0.64e. 0.16

ID: B

1

Physics 201 Midterm Exam 2Answer Section

MULTIPLE RESPONSE

1. ANS: A, B, C, D PTS: 1

MULTIPLE CHOICE

2. ANS: E PTS: 2 DIF: Average 3. ANS: D PTS: 1 DIF: Easy 4. ANS: E PTS: 3 DIF: Challenging 5. ANS: D PTS: 2 DIF: Average 6. ANS: E PTS: 2 DIF: Average 7. ANS: B PTS: 2 DIF: Average 8. ANS: E PTS: 2 DIF: Average 9. ANS: E PTS: 2 DIF: Average 10. ANS: B PTS: 1 DIF: Easy 11. ANS: D PTS: 1 DIF: Easy 12. ANS: A PTS: 2 DIF: Average 13. ANS: A PTS: 2 DIF: Average 14. ANS: B PTS: 1 DIF: Easy 15. ANS: B PTS: 2 DIF: Average 16. ANS: E PTS: 2 DIF: Average 17. ANS: D PTS: 3 DIF: Challenging 18. ANS: A PTS: 2 DIF: Average 19. ANS: A PTS: 2 DIF: Average 20. ANS: C PTS: 3 DIF: Challenging 21. ANS: E PTS: 1

Name: ______________________ Date: _________ ID: C

1

Physics 201 Midterm Exam 2

Information and Instructions

Student ID Number: ______________________

Section Number: ______________________

TA Name: ______________________

Please fill in all the information above.

Please write and bubble your Name and Student Id number on your scatron. Also fill in your section number under speacial codes. Finally question 1 asks you to fill in your teset ID code which is necessary to correctly grade your exam.

The exam has 20 questions (questions 2-21) and you have 1 hour and 15 mintues to complete the exam.

Please use 9.80 m/s^2 for the acceleration of gravity on the Earth.

.

____ 1. Please fill in your test ID codea. A c. Cb. B d. D

Name: ______________________ ID: C

2

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 2. An airplane travels 80.0 m/s as it makes a horizontal circular turn which has a 0.80-km radius. What is the magnitude of the resultant force on the 75-kg pilot of this airplane?a. 600 kN forward in the direction the plane’s velocity at any momentb. 0.60 kN inward toward the center of the circlec. 0.60 kN forward in the direction the plane’s velocity at any momentd. 0.95 kN upward and inward toward the center of the circlee. 0.74 kN upward

____ 3. A split highway has a number of lanes for traffic. For traffic going in one direction, the radius for the inside of the curve is half the radius for the outside. One car, car A, travels on the inside while another car of equal mass, car B, travels at equal speed on the outside of the curve. Which statement about resultant forces on the cars is correct?a. The force on B is four times the force on A.b. There is no net resultant force on either as long as they stay on the road while

turning.c. The force on B is half the force on A.d. The force on A is four times the force on B.e. The force on A is half the force on B.

____ 4. The coefficient of static friction for the tires of a race car is 0.950 and the coefficient of kinetic friction

is 0.800. The car is on a level circular track of 50.0 m radius on a planet where g = 2.45 ms2

compared to

Earth's g = 9.80 ms2

. If the car is to be able to travel at the same maximum speed without slipping on the

planet as on Earth, the radius of the track on the planet must be ____ times as large as the radius of the track on Earth.a. 4.00b. 0.250c. 0.500d. 2.00e. 1.00

____ 5. A skydiver of 75 kg mass has a terminal velocity of 60.0 m/s. At what speed is the resistive force on the skydiver half that when at terminal speed?a. 49 m/sb. 42 m/sc. 30 m/sd. 15 m/se. 36 m/s

Name: ______________________ ID: C

3

____ 6. If a dense 20.0-kg object is falling in air at half its terminal velocity, what is the drag force on the object at this moment?a. 69.3 Nb. 49.0 Nc. 24.5 Nd. 139 Ne. 98.0 N

____ 7. A 2.0-kg projectile moves from its initial position to a point that is displaced 20.0 m horizontally and 15 m above its initial position. How much work is done by the gravitational force on the projectile?a. +0.29 kJb. −0.29 kJc. −50 Jd. +30 Je. −30 J

____ 8. A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.50 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B?

a. 2.8 Jb. 2.2 Jc. 3.2 Jd. 1.6 Je. 1.0 J

Name: ______________________ ID: C

4

____ 9. A 10.0-kg block on a horizontal frictionless surface is attached to a light spring (force constant = 0.80 kN/m). The block is initially at rest at its equilibrium position when a force (magnitude P = 80.0 N) acting parallel to the surface is applied to the block, as shown. What is the speed of the block when it is 13 cm from its equilibrium position?

a. 0.52 m/sb. 0.85 m/sc. 0.64 m/sd. 0.89 m/se. 0.77 m/s

____ 10. When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction mk, then dragged back along the same path to its original position, the work done by friction isa. +mkmgd.b. 0.c. +2mkmgd.d. −2mkmgd.e. −mkmgd.

____ 11. Two clowns are launched horizontally from the same spring-loaded circus cannon with the spring compressed the same distance each time. Clown A has a 40-kg mass; clown B a 60-kg mass. The relation between their speeds at the instant of launch is

a. vB =32

vA.

b. vA =32

vB.

c. vB =32

vA.

d. vA =32

vB.

e. vA = vB.

Name: ______________________ ID: C

5

____ 12. A spring (k = 600.0 N/m) is placed in a vertical position with its lower end supported by a horizontal surface. The upper end is depressed 20.0 cm, and a 4.0-kg block is placed on top of the depressed spring, but not attached to the spring. The system is then released from rest. How far above the point of release will the block rise?a. 27 cmb. 31 cmc. 41 cmd. 36 cme. 20 cm

____ 13. A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70.0-kg athlete were to bicycle to the summit of a 0.50-km high mountain while expending power at this rate, she would reach the summit in ____ seconds.a. 460b. 1c. 500d. 35 000e. 1 000

____ 14. As an object moves from point A to point B only two forces act on it: one force is nonconservative and does −30 J of work, the other force is conservative and does +50 J of work. Between A and B,a. the kinetic energy of object increases, mechanical energy increases.b. the kinetic energy of object decreases, mechanical energy decreases.c. the kinetic energy of object decreases, mechanical energy increases.d. the kinetic energy of object increases, mechanical energy decreases.e. None of the above.

____ 15. A 3.0-kg object moving in the positive x direction has a one-dimensional elastic collision with a 5.0-kg object initially at rest. After the collision the 5.0-kg object has a velocity of 6.0 m/s in the positive x direction. What was the initial speed of the 3.0 kg object?a. 6.0 m/sb. 8.0 m/sc. 4.5 m/sd. 7.0 m/se. 5.5 m/s

____ 16. A ball of mass mB is released from rest and acquires velocity of magnitude vB before hitting the ground. The ratio of the kinetic energy the Earth acquires to the kinetic energy the ball acquires is

a.m B

m E

.

b.m E

m B

.

c.m B

m E

Ê

Ë

ÁÁÁÁÁÁÁÁÁÁ

ˆ

¯

˜̃̃˜̃̃˜̃̃˜

2

.

d. 1e. 0.

Name: ______________________ ID: C

6

____ 17. A 3.0-kg mass moving in the positive x direction with a speed of 10 m/s collides with a 6.0-kg mass initially at rest. After the collision, the speed of the 3.0-kg mass is 8.0 m/s, and its velocity vector makes an angle of 35° with the positive x axis. What is the magnitude of the velocity of the 6.0-kg mass after the collision?a. 3.5 m/sb. 4.7 m/sc. 2.2 m/sd. 2.9 m/se. 4.2 m/s

____ 18. A 4.2-kg object, initially at rest, "explodes" into three objects of equal mass. Two of these are determined to have velocities of equal magnitudes (5.0 m/s) with directions that differ by 90.0°. How much kinetic energy was released in the explosion?a. 53 Jb. 70 Jc. 64 Jd. 60 Je. 35 J

____ 19. Three particles are placed in the xy plane. A 40-g particle is located at (3, 4) m, and a 50-g particle is positioned at (−2, −6) m. Where must a 20-g particle be placed so that the center of mass of this three-particle system is located at the origin?a. (−1, 3) mb. (−1, 12) mc. (−1, 2) md. (−1, 7) me. (−1, −3) m

____ 20. Car A rear ends Car B, which has twice the mass of A, on an icy road at a speed low enough so that the collision is essentially elastic. Car B is stopped at a light when it is struck. Car A has mass m and speed v before the collision. After the collisiona. the momentum of car B is four times as great in magnitude as that of car A.b. each car has half the momentum.c. each car has half of the kinetic energy.d. car A stops and car B has momentum mv.e. car A stops and car B has momentum 2mv.

____ 21. Consider a physical situation like that in lab M-5, Projectile Motion. If the projectile has a mass of 0.010 kg is moving at 90.0 m/s, and is caught by a catcher of mass 0.50 kg, how far does the catcher rise?a. 0.51b. 0.32c. 0.080d. 0.64e. 0.16

ID: C

1

Physics 201 Midterm Exam 2Answer Section

MULTIPLE RESPONSE

1. ANS: A, B, C, D PTS: 1

MULTIPLE CHOICE

2. ANS: B PTS: 2 DIF: Average 3. ANS: C PTS: 1 DIF: Easy 4. ANS: A PTS: 3 DIF: Challenging 5. ANS: B PTS: 2 DIF: Average 6. ANS: B PTS: 2 DIF: Average 7. ANS: B PTS: 2 DIF: Average 8. ANS: B PTS: 2 DIF: Average 9. ANS: B PTS: 2 DIF: Average 10. ANS: D PTS: 1 DIF: Easy 11. ANS: B PTS: 1 DIF: Easy 12. ANS: B PTS: 2 DIF: Average 13. ANS: A PTS: 2 DIF: Average 14. ANS: D PTS: 1 DIF: Easy 15. ANS: B PTS: 2 DIF: Average 16. ANS: A PTS: 2 DIF: Average 17. ANS: D PTS: 3 DIF: Challenging 18. ANS: B PTS: 2 DIF: Average 19. ANS: D PTS: 2 DIF: Average 20. ANS: A PTS: 3 DIF: Challenging 21. ANS: E PTS: 1