# Lab : motion and gravity

**TUTORIAL:>>>>http://media.pearsoncmg.com/aw/aw_hewitt_cp_10/tutorials/motiongravity/cpf1_motiongravity.html?ssocheck=done&key=22709226621135338737172009&boogers=true**

Watch the tutorial on Motion and Gravity at The Physics Place. (You should NOT be prompted to login. If you cannot access this site, please contact Dr. Walker via email.)

### Ranking Tasks (10 points)

Rank each diagram by net force acting on cart. Rank the pictures from right (+) net force greatest to least, then zero net force, and finally from left (-) net force least to greatest. Assume each person pushes with exactly the same force (say 100 N). Does the net force depend on the amount of mass in cart?

A.

B.

C.

D.

E.

Multiple Choice (4 points)

In the diagram above, there is a rocket leaving the Earth and traveling to the Moon. Using the web site tutorial, choose the correct multiple choice response.

1. When the rocket is halfway between the Earth and the Moon, the force of gravity due to Earth is ____ the force of gravity due to the Moon.

a. equal to

b. about 10 times stronger than

c. about 100 times stronger than

2. The rocket must be ____ the distance from the Moon (compared to the distance from Earth) for the forces of gravity due to the Moon and Earth be equal.

a. half

b. one-tenth

c. one-hundredth

d. double

3. When the rocket is on the Earth, the force due to the Moon is ___.

a. twice as big as the Earth

b. one-hundredth smaller than Earth

c. one-tenth smaller than Earth

d. completely negligible

4. When the rocket is on the Moon, the force due to the Earth is ____.

a. twice as big as the Moon

b. one-hundredth smaller than Moon

### Ranking Tasks (10 points)

Rank each diagram by acceleration of the cart. Rank the pictures from right (+) acceleration greatest to least, then zero, and finally from left (-) acceleration least to greatest. Assume each person pushes with exactly the same force (say 100 N). Does the acceleration depend on the amount of mass in cart?

A.

B.

C.

D.

E.

Multiple Choice (6 points)

Each line represents an object traveling with different speeds. Using this chart above, choose the correct multiple choice answer.

1. How fast is object 1 moving after 5 seconds?

a. 1 m/s

b. 2 m/s

c. 5 m/s

d. 10 m/s

2. What is the acceleration of object 1?

a. 0.2 m/s 2

b. 0.5 m/s 2

c. 1.0 m/s 2

d. 2.0 m/s

23. How fast is object 2 moving after 2 seconds?

a. 0.2 m/s

b. 0.3 m/s

c. 1.0 m/s

d. 2.0 m/s

4. How fast is object 2 moving after 4 seconds?

a. 0.1 m/s

b. 0.25 m/s

c. 1.0 m/s

d. 2.0 m/s

5. Which two objects (2 or 3) have the greatest acceleration?

a. Object 2

b. Object 3

c. Neither

d. Cannot tell