The velocity of a particle decreases uniformly from `20 ms^(-1)` to zero in to `10 s` as shown in figure. If the mass of the particle is `2 kg`, the identify the correct statement.
.

Options

A. The net force acting on the particle is opposite to the direction of motion
B. The work done by friction force is `-400J`
C. The magnitude of friction force acting on the particle is `4 N`
D. All of the above.

Answer

A

Explanation

(a) Velocity is decreasing. Therefore, accleration (or net force) is opposite to the direction of motion.
(b) and (c ): some other forces (other than frication may also act which retard the motion.