Question

The work done in holding a $15kg$ suitcase while waiting in a bus for $45$ minutes is:
A) 675J
B) 40500J
C) 4500J
D) Zero

Answer 1

Hint: Work done is defined as the product of magnitude of displacement d and the component of force in the direction of displacement. Work done is force into displacement. Here, displacement of the bag is negligible.

Complete step by step answer:
What is displacement- Displacement is defined as, the word displacement itself implies that an object moves from one place to another, or has been displaced. Displacement can also be defined as to change in the position of an object. This is said to be displacement.
Since, the displacement of the man is zero. So, the work done is also zero. The man did not move from his place while waiting for the bus. It does not matter how much weight he is carrying and for how much time, the main thing that matters is the displacement.
If there is no displacement then no work is done.
So, displacement is zero.
Hence, work done will also be zero.
$\therefore$ The correct option is D

Note: The main thing is to remember, waiting is mentioned therefore there is no movement therefore no displacement is observed. Zero is the correct answer. And make sure here force is taken in Newton and displacement in meter. The main units are force, displacement, velocity. Force is defined as simply force means motion so when unopposed will change the motion of an object or push or pull upon an object resulting from the object's interaction with another object is said to be force. Velocity can be defined as the rate of change of the object's position with respect to time.