A body of mass 2 kg travels according to the law x(t) = p(t) + qt2 + rt3 where p = 3 m/s, q = 4 m/s2, and r = 5 m/s3. The force acting on the body at t=2 seconds is a) 136 N b) 134 N c) 158 N d) 68 N
Here, x(t)=pt+qt2+rt3 Where p=3ms−1,q=4ms−2,r=5ms−3 and m=2 kg Velocity, v=dtdx=dtd(pt+qt2+rt3)=p+2qt+3rt2 Acceleration, a=dtdv=2q+6rt At t=2s,a=2(4ms−2)+6(5ms−2)(2s) =8ms−2+60ms−2=68ms−2 The force acting on the body of mass 2 kg is F=ma=(2kg)(68ms−2)=136N
