Forces

Question 1

What are the 3 ways an object can accelerate?

Answer 1

-Speed up
-Slow down
-Change direction

Question 2

If an object is accelerating, what is happening to its velocity?

Answer 2

Its changing

Question 3

What are the two ways to tell if an object is not accelerating?

Answer 3

-Object is not moving
-Object is moving at a constant velocity

Question 4

If an object is not accelerating, what is happening to its velocity?

Answer 4

Its not changing

Question 5

Why do moving objects come to a stop on Earth?

Answer 5

There is an external force acting on the object

Question 6

What is Newton’s 1st law?

Answer 6

The law of inertia
-Objects at rest will stay at rest, and objects in motion will stay in motion unless acted on by a net external force

Question 7

What is the law of Inertia?

Answer 7

The tendency of an object to resist acceleration (a change in motion)

Objects want to keep doing what they are already doing.

Question 8

When talking about forces, should we consider space science or earth science?

Answer 8

space science - we are assuming no extra forces are being applied unless stated. So motion will never change.

Question 9

If a rocket ship is in deep space and it turns off its engine, what will happen?

Answer 9

It will keep moving with a constant velocity forever.

Question 10

Using Newton’s 1st law explain what will happen if you get into a car crash without your seatbelt on.

Answer 10

You will be thrown out the car.
-Since you are already moving, and there is no force being applied to slow you down you will keep moving.

Question 11

What causes acceleration?

Answer 11

A non-zero net force

Question 12

If an object is not moving, what is the net force on it?

Answer 12

zero

Question 13

If an object is moving at a constant velocity, what is the net force on it?

Answer 13

zero

Question 14

If an object is speeding up, what is the net force on it?

Answer 14

not zero

Question 15

If an object is slowing down, what is the net force on it?

Answer 15

not zero

Question 16

If an object is changing directions, what is the net force on it?

Answer 16

not zero

Question 17

What does it mean when an objects net force does not equal zero?

Answer 17

The object is accelerating

Question 18

Using Newton’s 1st law explain what will happen if you get into a car crash with your seatbelt on.

Answer 18

You will stay in the car.
-Even though you are already moving. The seat belt will apply a force to slow you down.

Question 19

Is it harder or easier for object with more mass to accelerate?

Answer 19

Harder - more mass means more inertia

Question 20

Is it harder or easier for object with less mass to accelerate?

Answer 20

Easier - less mass means less inertia

Question 21

What direction is the force of gravity (weight)

Answer 21

Always down

Question 22

What direction is the Normal force?

Answer 22

Perpendicular to the surface

Question 23

What direction is the friction force?

Answer 23

Opposite of motion

Question 24

What value do we use for gravity on Earth?

Answer 24

-10 m/s^2

Question 25

What equation is used to calculate weight (force of gravity)

Answer 25

weight = (mass) * (gravity)
w = mg

Note: gravity is where you are at. So if on the moon, use the moons gravity.

Question 26

A cart is on a frictionless surface and is moving with a constant velocity of 5 m/s. What amount of force is required to keep this cart in motion?

Answer 26

No force is needed.

The cart has a constant velocity, so it is not accelerating and thus needs no force.

Question 27

When an object is in equilibrium, what does that indicate about its net force?

Answer 27

The net force equals zero.
- All forces cancel out.

Question 28

What is the difference between weight and mass?

Answer 28

Weight changes
Mass is always the same.