Ch. 9 part a

Question 1

TRUE OR FALSE

Force is measured in joules.

Answer 1

False

Question 2

TRUE OR FALSE

The spot where a lever turns is called a fulcrum.

Answer 2

TRUE

Question 3

TRUE OR FALSE

The resistance force works against the effort.

Answer 3

TRUE

Question 4

TRUE OR FALSE

Galileo is credited with formulating the three laws of motion we use today.

Answer 4

FALSE

Question 4

TRUE OR FALSE

A simple machine combines two or more machines to make work easier.

Answer 4

FALSE

Question 5

TRUE OR FALSE

A block and tackle combines multiple fixed and moveable pulleys.

Answer 5

TRUE

Question 6

1. an object at rest stays at rest and an object in motion stays in motion
2. force = mass X acceleration
3. “action and reaction”

A rocket is launched, expelling gases downward to the ground, causing the rocket to move upward is 1, 2, or 3?

Answer 6

3. “action and reaction”

Question 7

1. an object at rest stays at rest and an object in motion stays in motion
2. force = mass X acceleration
3. “action and reaction”

You are sledding the sled stops when it hits a branch hidden in the snow. You keep moving and slide off the sled. Is that an example of 1, 2, or 3?

Answer 7

1. an object at rest stays at rest and an object in motion stays in motion

Question 8

1. an object at rest stays at rest and an object in motion stays in motion
2. force = mass X acceleration
3. “action and reaction”

It took one student to pick up a box filled with feathers and two students to pick up the same-size box filled with books.

Answer 8

2. 2. force = mass X acceleration

Question 9

Which unit is used to measure work?

a. newton
b. cubic centimeter
c. mile
d. joule

Answer 9

d. joule

Question 10

In what way does friction affect motion?

Answer 10

Friction is a force that keeps objects moving against other objects. It is what helps us move and walk.