Physics Review

Newton's Laws of Motion

1st Law: An object at rest will remain at rest, and an object in motion will remain in motion unless acted on by an outside force.

2nd Law: An object accelerates because a force acts on it. The larger the force, the greater the acceleration. The larger the mass, the greater force needed to accelerate it.

3rd Law: For every action force, there is an equal and opposite reaction force.

Friction

Friction is a force opposing the motion between two surfaces. For example: Tires on roadway.

VELOCITY

• Velocity of an object is its speed combined with the direction of the motion

• Just add the direction to the speed and you have velocity

• An example of velocity would be 70m/s south

Multiple Choice

Is this a balanced or unbalanced force?

• Balanced

• Unbalanced

Multiple Choice

What is the net force?

• 10 N to the right

• 10 N to the left

• 130 N to the left

• 130 N to the right

Multiple Choice

What is the net force?

• 10 N to the left

• 10 N to the right

• 50 N to the right

• 60 N to the left

Multiple Choice

What is the net force?

• 17 N Right
• 3 N Right
• 3 N Left
• 17 N Left

Multiple Choice

What does this graph represent?

• Constant Speed
• Acceleration
• Not moving

Multiple Choice

Calculate the average speed (in meter/sec) if a cheetah runs 180 meters in 10 seconds.

• 198 m/sec
• 170 m/sec
• 12 m/sec
• 18 m/sec

Multiple Choice

How long did it take this object to travel 10 m?

• 0 s
• 10 s
• 15 s
• 20 s

Multiple Choice

At 60 seconds, how far had this object traveled? 

• 0 m
• 10 m
• 20 m
• 40 m

Multiple Choice

What does this graph represent?

• Constant speed
• Acceleration
• Not moving

Multiple Choice

What does this graph represent?

• Constant speed
• Acceleration
• Not moving

Multiple Choice

What is happening at C?

• Stationary
• Accelerating
• Fast steady speed; moving away from the starting position
• Slower steady speed; moving away from the starting position

Multiple Choice

How long will a 100 mile trip take if the speed is 40 miles per hour?

• 400

• 2.5 hours

• 4,000 hours

• 2.5 miles

Multiple Choice

Because of inertia, a resting object will remain at ________.

• rest
• a constant speed
• school
• inertia 

Multiple Choice

Because of inertia, a moving object will keep ________ unless acted on by an unbalanced force.

• at rest

• moving

• in one spot

• inertia

Multiple Choice

The tendency of an object to resist a change in motion is...

• inertia
• kinetic energy
• vector
• net force

Multiple Choice

• F

• G

• H

• J

Multiple Choice

Are the forces acting on the sled in Section 1 balanced or unbalanced? The track is smooth and frictionless.

• Balanced
• Unbalanced

Multiple Choice

Why did Izzy fall when playing tug of war?

• he tripped
• unbalanced forces
• balanced forces
• he was pushed

Multiple Choice

Sometimes tectonic plates do not move easily past one another, and the plates become stuck. Forces build up, and when the plates finally move, tension is released, as shown below. The sudden movement of the plates is caused by -

• the mass of the plates
• the weight of the plates
• unbalance forces
• gravitational force

Multiple Choice

A bird flying south at 64 km/hr is an example of:

• Speed

• Velocity

Multiple Choice

A ball rolling west at 5 cm/s is an example of:

• Speed

• Velocity

Multiple Choice

A car traveling 300 miles in 5 hours is an example of:

• speed

• velocity

Multiple Choice

A train travels 500 km north in 2 hours. What is the train's velocity?

• 250 km/hr

• 250 km/hr north

• 500 km/s

• 500 km/s north

Multiple Choice

What is the person doing from 5 seconds to 10 seconds?

• Walking 
• Running
• Standing Still 
• Walking Fast

Multiple Choice

slow down

• Speed
• Velocity
• Acceleration

Multiple Choice

change in velocity

• Speed
• Velocity
• Acceleration

Multiple Choice

72 m/s

• Speed
• Velocity
• Acceleration

Multiple Choice

How much force is needed to accelerate a 25kg bowling ball at 2m/s².

• 50N

• 5N

• 12.5N

• 100N

Multiple Choice

A force of 250 N is applied to an object that accelerates at a rate of 5 m/sec².  What is the mass of the object?

• 100kg 
• 1,250kg
• 50kg
• 5kg

Multiple Choice

What is the tendency of an object to resist a change in motion?

• Action - Reaction

• FMA

• Inertia

Multiple Choice

Which law is this picture an example of?

• Law of Inertia

• Law of Force and Acceleration

• Law of Action / Reaction

Multiple Choice

• 3.4 m/s2

• 35 m/s2

• 50 m/s2

• 5 m/s2

Multiple Choice

What can a force do?

• all of the above
• start a motion
• stop a motion
• change the direction of the motion

Multiple Choice

The picture is an example of Newton's...

• 1st Law

• 2nd Law

• 3rd Law

Multiple Choice

A person’s body is thrown outward as a car rounds a curve on a highway.

• Newton's 1st Law

• Newton's 2nd Law

• Newton's 3rd Law

• None of them

Multiple Choice

A magician pulls a tablecloth out from under dishes and glasses on a table without disturbing them.

• Newton's 1st Law
• Newton's 2nd Law
• Newton's 3rd Law
• None of them

Multiple Choice

What is the tendency of an object to resist a change in motion?

• coffee
• motion
• inertia
• gravity

Multiple Choice

Objects with greater _________ also have greater inertia.

• speed
• mass
• temperature
• friction

Multiple Choice

A swimmer pushes water back with her arms, but her body moves forward.

• Newton's 1st Law

• Newton's 2nd Law

• Newton's 3rd Law

Multiple Choice

As the fuel in a rocket ignites, the force of the gas expansion and explosion pushes out the back of the rocket and pushes the rocket forward.

• Newton's 1st Law

• Newton's 2nd Law

• Newton's 3rd Law

Multiple Choice

When you are riding in a car and the car suddenly stops, your body continues to go forward.

• Newton's 1st Law

• Newton's 2nd Law

• Newton's 3rd Law

Multiple Choice

45 m/s² is the... 

• Mass
• Force 
• Acceleration
• weight

Multiple Choice

A 20 kg bike accelerates at 10 m/s².  what was the force?

• 25 Newtons
• 20 Newtons
• 200 Newtons
• 10 Newtons

Multiple Choice

Force is measured in.....

• kg, mg or g

• m/s 2

• m/s

• N

Multiple Choice

If you increase the mass on an object, its acceleration

• decreases
• stays the same
• also increases
• stops

Multiple Choice

How much force is needed to accelerate a 3kg skateboard at 5m/s^2. 

• 8N
• 1.6N
• 0.6N
• 15N

Multiple Choice

What is the unit for FORCE?

• N (Newtons)

• g (grams)

• lbs (pounds)

• m/s meters per second

Multiple Select

List the three (3) possibilities that an object might demonstrate when subjected to an unbalanced force:

(You must choose 3 answers)

• Speed Up

• Leave Our Atmosphere

• Slow Down

• Levitate In The Air

• Change Direction

Multiple Choice

Unit of mass

• m/s 2
• m/s
• newtons
• kg

Multiple Choice

Which is the best example of Newton's First Law of Motion?

• a basketball thrown in the air falls to the ground
• a soccer ball remains motionless until it is kicked by a player
• a baseball player swings at an approaching ball
• an ice skater pushes back from a wall and moves backwards