A body of mass 2 kg travels according to the law $x (t) = p t + q t^{2} + r t^{3}$ where $p = 3 m s^{- 1}, q = 4 m s^{- 2}$ and $r = 5 m s^{- 3}$ . The acting on the body at t=2 seconds is

Question

A body of mass 2 kg travels according to the law x-t-pt-qt-2-rt-3 where p-3ms-1- q- 4ms-2-  and r-5 ms-3- The acting on the body t-2 seconds is136 N134 N68 N158 N

Toppr Admin · Accepted Answer

Here- x-t-pt-qt2-rt3Where p-3ms-x2212-1-q-4ms-x2212-2-r-5ms-x2212-3 and m-2 kgVelocity- v-dxdt-ddt-pt-qt2-rt3-p-2qt-3rt2Acceleration- a-dvdt-2q-6rtAt t-2s-a-2-4ms-x2212-2-6-5ms-x2212-2-2s-8ms-x2212-2-60ms-x2212-2-68ms-x2212-2The force acting on the body of mass 2 kg is-xA0-F-ma-2kg-68ms-x2212-2-136N

A body of mass 2 kg travels according to the law x(t)=pt+qt2+rt3 where p=3ms−1,q=4ms−2 and r=5ms−3. The acting on the body at t=2 seconds is136 N134 N68 N158 N

Here, x(t)=pt+qt2+rt3Where p=3ms−1,q=4ms−2,r=5ms−3 and m=2 kgVelocity, v=dxdt=ddt(pt+qt2+rt3)=p+2qt+3rt2Acceleration, a=dvdt=2q+6rtAt t=2s,a=2(4ms−2)+6(5ms−2)(2s)=8ms−2+60ms−2=68ms−2The force acting on the body of mass 2 kg is F=ma=(2kg)(68ms−2)=136N

A body of mass 2 kg travels according to the law $x (t) = p t + q t^{2} + r t^{3}$ where $p = 3 m s^{- 1}, q = 4 m s^{- 2}$ and $r = 5 m s^{- 3}$ . The acting on the body at t=2 seconds is
136 N
134 N
68 N
158 N