Units
Newton's 1st Law
Newton's 2nd Law and Acceleration
Newton's 3rd Law
100
What are the units for acceleration?
m/s2
100
Newton's 1st law is sometimes called the law of _____. This word describes an object's resistance to acceleration.
inertia
100
What quantity is calculated by mass * acceleration? (Be specific!)
NET force
100
Newton's 3rd Law states that for every action force there is an _____ and ____ reaction force.
equal and opposite
200
What are the units for force?
Newton's (N)
200
True or False: Without a net force, light moving objects tend to slow to a stop.
False
200
What happens to the acceleration of an object when its net force is halved and its mass is doubled?
The acceleration is 1/4 of what it was.
200
True or False: All forces that are equal in magnitude and opposite in direction are Newton's 3rd Law pair forces.
False
300
What are the units for mass?
kilograms (kg)
300
A worker pushes a 50 N box at a constant speed of 3 m/s using a 25 N force. What is the net force acting on the box?
Zero. The net force for anything at constant speed is zero!
300
A car accelerates from rest to 15 m/s in 3 s using a 10,000 N force. What is the car's mass?
2000 kg
a=5 m/s2 so 10000=m*5.
300
True or False: Newton's 3rd Law pair forces must be the same kind of force (both gravity, both tension, etc.)
True
400
What are the units for weight?
Newtons (N)
400
What is the magnitude of force T?
500 N
400
What is the acceleration of a 500 kg elevator experiencing a 6000 N upward force?
2 m/s2
Weight = 5000 N so net force = 1000 N
1000 = 500*a
400
A trampoline pushes upward on a kid with 300 N of force. By Newton's 3rd law, the ____ (object) pushes _____ (direction) on the _____ (object) with _____ N (magnitude of force).
kid pushes downward on the trampoline with 300 N
500
What are the SI units (some combination of kg, m, and s) for Force? Hint, think F=ma
kg m/s2
500
A worker pushes on a 10 kg box at constant speed with a force F. The box experiences a friction force equal to 1/4 its weight. What is the magnitude of the force F?
25 N
500
A 600 kg elevator initially moving at 8 m/s comes to a stop in 4 s experiencing a downward acceleration. What is magnitude of the upward tension force acting on the elevator?
4800 N
a=2 m/s2 downward so net force = 1200 N downward.
The weight is 6000 N so there must be a 4800 N upward force (4800-6000=-1200)
500
Identify a 3rd law pair of forces that is occurring around you right now. Provide the name of the forces like force ___ on ___ and the directions.
Something like:
Force table on notebook pushing upward
Force notebook on table pushing downward