Nature of Physical World Questions And Answers.

1.When a body falls freely under gravity, then the work done by the gravity is?
A. Positive
B. Negative
C. Zero
D. Infinity

2.When a body slides against a rough horizontal surface, the work done by friction is?
A. Positive
B. Zero
C. Negative
D. Constant

3.For a body moving in a circular path, the work done by the centripetal force is?
A. Negative
B. Positive
C. Constant
D. Zero

4.A gardener pushes a lawn roller through a distance of 20m. If he applies a force of 20kg weight in a direction inclined at 60° to the ground, find the work done by him. (g=9.8m/s2)?
A. 400J
B. 1960J
C. 250J
D. 2514J

5.A person is holding a bucket by applying a force of 10N. He moves a horizontal distance of 5m and then climbs up a vertical distance of 10m. Find the total work done by him?
A. 50J
B. 150J
C. 100J
D. 200J