Download Quiz: Newton`s Laws

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Quiz: Newton’s Laws
Newton’s First Law: An object at rest stays at rest and an object in motion stays in motion until
an unbalanced force is exerted upon it.
Newton’s Second Law: The acceleration of an object is directly proportional to the net force
exerted upon it and inversely proportional to its mass.
Newton’s Third Law: When one object exerts a force on a second object, the second object
exerts a force on the first object that is equal in magnitude and opposite in direction.
Multiple Choice (1 point each) Place the letter corresponding to your choice on the line to the
left of the question.
__________ 1. Acceleration is caused by:
A.) Balanced Forces.
B.) Unbalanced Forces.
C.) All of the above.
D.) None of the above.
__________ 2. If an object is at rest, it will tend to stay at rest because of:
A.) Acceleration
B.) Forces
C.) Inertia
__________ 3. A moving object will continue moving in a straight line unless it is acted upon by
A.) An unbalanced force.
B.) A balanced force.
C.) A small force.
D.) A large force.
__________ 4. Forces can cause objects to:
A.) Stop moving.
B.) Change direction.
C.) Start Moving.
D.) All of the above.
__________ 5. We don’t generally see objects continuing to move forever because of the
presence of :
A.) friction
B.) inertia
C.) balanced forces
D.) gravity
__________ 6. For every action, the reaction is:
A.) Equal in size and in the same direction.
B.) Equal in size and in the opposite direction.
C.) Unequal in size and in the opposite direction.
D.) Unequal in size and in the same direction.
__________ 7. The Earth exerts a force of 1N downward on your textbook. Therefore,
A.) Your textbook exerts a force of 1N upward on the Earth.
B.) Your textbook exerts a very small upward force on the Earth.
C.) Your textbook does not exert a force on the Earth.
D.) Your textbook exerts a force of 1N downward on the Earth.
__________ 8. Mass can be said to be a measure of an object’s:
A.) Weight
B.) Volume
C.) Density
D.) Inertia
__________ 9. A car is traveling at a constant 5m/s in a straight line to the right.
A.) There is 0N of net force acting on the car.
B.) There is a net force acting on the car. The net force is directed to the
right.
C.) There is a net force acting on the car. The net force is directed to the
left.
__________ 10. A ball is falling to the ground. It is accelerating towards the ground.
A.) There is 0N of net force acting on the ball.
B.) There is a net force acting on the ball. The net force is directed up.
C.) There is a net force acting on the ball. The net force is directed down.
__________ 11.
__________ 12.
Johnny lifts up the teddy bear. If Johnny exerts twice as much force
on the teddy bear, then the teddy bear’s acceleration will:
A.) stay the same.
B.) Increase
C.) decrease.
Jack wants to give the airplane a larger acceleration. He needs to:
A.) exert the same amount of force.
B.) exert more force.
C.) exert less force.
Use the following pictures for questions #13-14.
__________13. Which animal has the most mass?
A.) Elephant
B.) Cat
C.) Fish
__________ 14. Which animal has the least inertia?
A.) Elephant
B.) Cat
C.) Fish
__________ 15.
The train is going round and round the tracks. It gets to a
tight turn and runs off the tracks. Which path will the train take?
A
B
C
Use the following situation for questions #16 and 17.
Imagine Maggie is pulling a wagon to the left () with a force of 20N and Greg is pushing the
wagon to the left () with a force of 15N.
__________ 16. What is the total (net) force on the wagon?
A.) 0 Newtons
B.) 35 Newtons left
C.) 35 Newtons right
D.) 5 Newtons left
__________ 17. The wagon must be:
A.) at rest
B.) moving at a constant velocity
C.) accelerating to the left
D.) accelerating to the right.
__________ 18. Imagine Sam is pulling the teddy bear to the left () with a force of 4N and
Stephanie is pulling the teddy bear to the right () with a force of 8N.What is the total (net)
force on the teddy bear?
A.) 12 N to the right
B.) 4 N to the right
C.) 4 N to the left
D.) 0 N
Use the following situation for questions #19 and 20.
Imagine Chris is pulling a present to the left () with a force of 5N and Pat is pulling the
present to the right () with a force of 5N
__________ 19. What is the total (net) force on the present?
A.) 5N to the left
B.) 5N to the right
C.) 10N to the left
D.) 0N
__________ 20. The present must be:
A.) accelerating to the right
B.) accelerating to the left
C.) at rest
D.) not accelerating
Short Answer and Calculations (points marked)
1. You are driving along Washington Street at a speed of 25 miles per hour. Out of nowhere a
pedestrian steps into the crosswalk and you slam on the brakes of the car.
a.) Everyone in the car feels as if they are thrown forwards. Explain in terms of one or more of
Newton’s Laws. Use Complete Sentences. (2 points)
b.) The seatbelts prevent the people from flying through the windshield. In terms of forces and
one or more of Newton’s Laws, what are the seatbelts doing? Use Complete Sentences. (2
points)
2. You are pushing a friend on a swing. You apply a force of 200 Newtons to your friend who
has a mass of 50kg. Find your friend’s acceleration. (You’ll need to find the appropriate formula
on the MCAS formula sheet.) SHOW YOUR WORK! (3 points)
3. Calculate the weight of an object which has a mass of 30kg. SHOW YOUR WORK. (3 points)
Remember: weight = m  g, where g = 10 m/s2.