A force acts on a body but does negative work. This means the force
- A. acts in the same direction as the displacement
- B. has a component opposite to the displacement, so it removes energy from the body
- C. does no work at all
- D. acts at right angles to the displacement
Explanation
Friction and air resistance always oppose the motion and therefore always do negative work, reducing the kinetic energy. A force at right angles does zero work rather than negative work, which is the distinction being tested. Gravity does negative work on a body moving upwards and positive work as it comes back down.
Related questions
A force of 50 N pulls a box 4 m along the floor at 60 degrees to the horizontal. The work done is
The work done by the centripetal force on a body moving in a circle at constant speed is
Work done by a force is zero when the angle between the force and the displacement is
A porter carries a suitcase horizontally across a platform at constant speed. The work done by the porter against gravity is
Work is done on a body only when