Physics 1D03 - Lecture 25

TEST – Thursday at 7pm

• The test will cover things we have done in class up to Lecture 9 (Chapter 1,2,4,5.1-5.4, 5.6, 6.1-6.3 and 8)

• Momentum will NOT be on the test• Please look over old test (available online)• Make sure you’re up on your reading !• Review error calculations (done in lab)• Look over CAPA problems (the easier ones!)

• This test is worth 15% of your mark• There are 15 multiple choice questions on the test

Physics 1D03 - Lecture 25

TEST

Bring:

- your student card- your calculator - pen or pencil

- please wait for TAs to let you in the room- if you’re not sure about a question – ASK !!!- remain quite near the end – other will still be writing!

- do easier questions first, then go back

Physics 1D03 - Lecture 25

• Kinematics: average velocity, acceleration, vectors, displacement, d=vt+1/2at2, v=vo+at, v2

2=v12+2ad,

projectile motion

• Dynamics: Free-body diagrams, forces ΣF=ma, friction, ramp and pulleys, vectors

Physics 1D03 - Lecture 25

x

v

a

t

t

t

Graphs of x(t), v(t), a(t)

Physics 1D03 - Lecture 25

Projectile Motion

• A plane if flying horizontally at 40m/s when it drops a package. If the package lands 181m ahead of the point above which it was dropped, when was it dropped and from what height ?

dv

dh

Physics 1D03 - Lecture 25

Friction

• You are pushing a 100kg fridge over a floor with μs=0.5 and μk=0.3 with a force of 290N. What is the magnitude of the frictional force between the fridge and the floor.

Physics 1D03 - Lecture 25

Another look at tension

• Two blocks are being pulled on a frictionless surface by a force Fa to the left. The mass of the first block is m and the one behind 5m. What is the tension between the blocks?

m5m

Fa

Physics 1D03 - Lecture 25

Contact Force

• Two blocks, one of mass m1 and the other of mass m2 are being pushed by a force F on a frictionless surface.

Determine their acceleration and the magnitude of the contact force.

m2

m1 F

Physics 1D03 - Lecture 25

Tension

• A mass m=20.4kg is suspended by two ropes as show in the diagram below. θ1=60 and θ2=45. Determine the tension in the strings.

θ1

θ2

Physics 1D03 - Lecture 25

Inclines

• Find a.

m 1 m 2

Physics 1D03 - Lecture 25

Pulleys

Consider the more elaborate Atwood’s machine shown.

a2

Assuming the rope and pulleys are ideal, the relation between the accelerations will be:

212

1

221

1

21

21

and of values the on depends aa

ratio The )

)

2 )

)

mmd

aac

aab

aaa

m2

m1

a1

Physics 1D03 - Lecture 25

More question to be added later… (I had to go home)