Name: ______________________________________ Date: _________________ Period: _____
Circle the best answer:
1. The forces shown above are PUSHING / PULLING forces.
2. The forces shown above are WORKING TOGETHER / OPPOSITE FORCES.
3. The forces are EQUAL / NOT EQUAL.
4. The forces DO / DO NOT balance each other.
5. The resultant force is 1000 N TO THE RIGHT / 1000 N TO THE LEFT /ZERO.
6. There IS / IS NO motion.
7. The forces shown
are PUSHING /
PULLING forces.
8. The forces shown
are WORKING
TOGETHER / OPPOSITE
FORCES.
9. The forces are
EQUAL / NOT EQUAL.
10. The forces DO / DO
NOT balance each
other.
11. The stronger force is pulling to the RIGHT / LEFT.
12. The weaker force is pulling to the RIGHT / LEFT.
13. Motion is to the RIGHT / LEFT.
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Calculations:
1. How much force is needed to accelerate a 66 kg skier at 2 m/sec2?
2. What is the force on a 1000 kg elevator that is falling freely at 9.8 N/kg?
3. What is the acceleration of a 50 kg object pushed with a force of 500 newtons?
4. The mass of a large car is 1000 kg. How much force would be required to accelerate the car at a rate of 3
m/sec2?
5. A 50 kg skater pushed by a friend accelerates 5 m/sec2. How much force did the friend apply?
6. 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?
7. A bowling ball rolled with a force of 15 N accelerates at a rate of 3 m/sec2; a second ball rolled with the
same force accelerates 4 m/sec2. What are the masses of the two balls?
8. If a 60 kg person on a 15 kg sled is pushed with a force of 300 N, what will be person’s acceleration?
9. A force of 20 N acts upon a 5 kg block. Calculate the acceleration of the object.
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10. An object of mass 300 kg is observed to accelerate at the rate of 4 m/s2. Calculate the force required to
produce this acceleration.
11. A 5 kg block is pulled across a table by a horizontal force of 40 N with a frictional force of 8 N opposing the
motion. Calculate the acceleration of the object.
12. An object of mass 30 kg is in free fall in a vacuum where there is no air resistance. Determine the
acceleration of the object.
13. An object of mass 30 kg is falling in air and experiences a force due to air resistance of 50 newtons.
a. Determine the net force acting on the object and
b. Calculate the acceleration of the object.
14. A 45N girl sits on a 8N bench. How much work is done on the bench?
Remember that work = force x distance. What is the work?
15. A boy lifts a 30N dragon 2 meters above the ground. How much work did the boy do on the dragon? What
is the work?
16. Which of the following is having work done on it? (Circle all that apply.)
a. a grocery bag as you lift it up
b. a crane moving dirt
c. a crate as you push it along the floor
d. a person sitting on a bench
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17. Suppose you want to calculate how much work it takes to lift a 160 N barbell. Besides the mass of the
barbell, what other information do you need to know?
a. the shape of the weights
b. how high the barbell is being lifted
c. the strength of the person doing the lifting
d. None of the above
18. If you are in a car that is being pulled down a 56.0 m path with a force of 12.5 Newton’s (N), what is the
“work” done on the car?
19. A crane does work of 13,500 J with a force of 5200 N to lift a beam. How far can the beam be lifted (in
meters)?
20. A 600 kg great white shark is lurking below an observation cage. His movement is being studied from a
series of motion sensors below the boat. The shark leisurely charges the cage, strikes it and makes the cage
rattle. Later, the shark returns for another run at the cage. The shark strikes the cage with 12,800 N of force.
The shark traveled for 10 m in making its run. The cage is designed to withstand 124,500 N-m of “work” before
it breaks. Should the man in the cage be worried? Explain.
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