Acceleration and Gravity

Chapter 4.4, Physics 2

Representing 1D motion

• Motion • horizontally

• Motion • vertically

Acceleration, speeds up

• A car is stopped at a red light. When the light turns green, the car speeds up to 80 m/s in 5 s. What is the acceleration of the car?

Acceleration, speeds up

•What is the acceleration of a train that travels from 100m/s to 120m/s in 10s?

Acceleration, speeds up

•A boat accelerates at a rate of 6.0 m/s2 down the river. How much time will it take the boat to speed up to 70 m/s?

Acceleration, Slows down

• Carlos throws a boomerang into the air with an initial velocity of 5 m/s. The boomerang takes 5 s to reach a velocity of 3 m/s. What is the boomerang’s acceleration?

Acceleration, gravity

• A gorilla falls out of the tree with an acceleration of 25 m/s2. If she hits the ground in 5 s, what is the poor gorilla’s change in velocity?

Acceleration, gravity

• An apple falls from a tree and reaches the ground in 4seconds with a velocity of 40m/s. What is the acceleration?

Velocity and Acceleration

• If

or v = atv = gt g = -

10m/s^2

Position equation

• A race car accelerates uniformly from 18.5 m/s to 46.1 m/s in 2.47 seconds. Determine the acceleration of the car and the distance traveled.

• Problem 4: http://www.physicsclassroom.com/class/1DKin/Lesson-6/Sample-Problems-and-Solutions

Gravity

• Distance = (1/2)(acceleration)(time)2

d = (1/2)at2

Position equation

• A feather is dropped on the moon from a height of 1.40 meters. The acceleration of gravity on the moon is 1.67 m/s^2. Determine the time for the feather to fall to the surface of the moon.

• Problem 5: http://www.physicsclassroom.com/class/1DKin/Lesson-6/Sample-Problems-and-Solutions