A block of mass `2kg` is free to move along the x-axis. It is 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)` vaies with t as shown in figure. The kinetic energy of the block after `4.5s` is

Options

A. 4.50 J
B. 7.50 J
C. 5.06 J
D. 14.06 J

Answer

C

Explanation

Area under F – t curve = 4.5 kg m/s `" " KE = 1/2 (2) ((4.5)/(2))^(2) = 5.06 J`