Review questions!
Forces 1 spin
1. Define force.
2. What is net force?
Is the net force zero or not?
3. mace being swung in circle with constant speed ______
4. cat dropped from rest ______
5. cat falling at terminal velocity ______
6. phone sitting on table ______
7. cat being caught ______
8. space probe floating through empty space (engines off) ______
2 spins
9. Use the factor label method to convert the weight of a 8.0 lb baby to Newtons. Show your work.(3)
10. Use the factor label method to convert the weight of a 1600 N object to pounds. Show your work. (3)
11. If an object is accelerating, it could be doing one of three things. List them.
12. What is the weight of a 4.0 kg object?
3 spins
13. Student 1 and student 2 are fighting over a science book. Student 1 pulls the book with a force of 150 N to the right. Student 2 pulls the book with a force of 180 N to the left.
a. Draw a force diagram.
b. What is the net force on the book?
c. Will the book accelerate? If so, in what direction?
14. Student 1 is pushing a desk across the floor. Student 1 is pushing with a force of 60 N to the right and the force of kinetic friction on the desk is 60 N.
a. Draw a force diagram, labelling all 4 forces.
b. What is the net force on the desk?
c. Will the book accelerate? If so, in what direction?
15. What is the weight of a 800 g object?
Friction! 1 spin
1. If you push to the left, friction pushes
2. Which type of friction is the strongest?
3. Which are the two kinds of kinetic friction?
4. List 2 ways to reduce friction.
5. List 2 ways to increase friction.
2 spins
6. Define friction – 3 key parts! (force, touching, resists motion)
7. What 2 things cause friction?
8. A student is pushing a desk across the floor. Another student sits on the desk. How does this affect the force of friction? Why?
9. Give 1 situation where friction is helpful and explain why.
10. Give 1 situation where friction is harmful and explain why.
11. List 2 conditions that reduce friction on the road and explain how each reduces friction.
Air Resistance 1 spin
1. Give 1 situation where air resistance is good and explain why.
2. Give 1 situation where air resistance is bad and explain why.
3. What’s the most streamlined shape?
4. As speed increases, what happens to the force of air resistance?
5. The speed at which a falling object stops accelerating is its _____?
2 spins
6. List the 2 causes of air resistance.
7. What is the terminal velocity of a penny?
8. What is the terminal velocity of a raindrop?
9. What is the terminal velocity of a human?
10. How can you avoid hydroplaning? (drive slower)
11. What should you do if you are driving a car and it starts hydroplaning?
(Steer towards open space & ease off the gas)
12. Give 2 ways to minimize air resistance.