Answers to Physics Module Questions - Module #5

1. A pebble flies up and hits the windshield of a truck travelling at 80 km/hr. The force of the impact is
1. greater on the pebble
2. lesser on the pebble
3. greater on the pebble than on the windshield, if the pebble shatters
4. greater on the windshield than on the pebble, if the windshield shatters
5. the same on pebble and on the windshield
6. none of the above

2. As a meteor falls towards earth, it is attracted by earth's gravity. What is the reaction to this force?
1. air resistance
2. the meteor's inertia
3. the earth's inertia
4. the earth's gravity
5. earth is attracted by the meteor's gravity
6. the meteor is attracted by all the particles in the universe
7. earth is attracted by all the particles in the universe

3. A person who has a mass of 100 kg is attracted to the earth by a force of about 1000 N. The force with which this person attracts the earth is
1. zero
2. much smaller
3. 10 N
4. 100 N
5. 500 N
6. 1000 N
7. 2000 N
8. none of the above

4. Two people are in a tug-of-war. Each person pulls the rope with a force of 500 N. What is the tension in the rope?
1. 1000 N
2. zero
3. 250 N
4. 500 N
5. depends on the diameter of the rope
6. none of the above

5. Every force has an equal and opposite reaction. A force and its reaction
1. cancel each other
2. are two interactions
3. are parts of a single interaction
4. have double the effect compared to a force without its reaction
5. none of the above