Power applied to a particle varices with time as `P =(3t^(2)-2t + 1)` watt, where t is in second. Find the change in its kinetic energy between time `t=2s` and `t = 4 s` .

Options

A. 32 J
B. 46 J
C. 61 J
D. 102 J

Answer

B

Explanation

(b) Change in kinetic energy of the particle
`DeltaKE=W=int_(2)^(4)Pdt=int_(2)^(4)(3t^(2)-2t+1)dt=[t^(3)-t^(2)+]_(2)^(4)=46J`