A block of mass `2 kg` is free to move along the `x`-axis. It at rest and from `t = 0`onwards it is subjected to a time-dependent force `F(t)` in the `x` direction. The force `F(t)` varies with `t` as shown in the figure. The kinetic energy of the block after `4.5` seconds is

Options

A. (a) `4.50J`
B. (b) `7.50J`
C. (c) `5.06J`
D. (d) `14.06J`

Answer

C

Explanation

Area under `F-t` curve `=4.5kgms^-1`
`KE=1/2(2)(4.5/2)^2=5.06J`