A body of mass 2kg travels according to the law x(t)=pt+qt^2+rt^3 where p=3m/s q=4m/s^2 and r=5m/s^3.The force acting on the body at t=2s is

Shailendra Kumar Sharma
188 Points
4 years ago
Force acting on a body is given by F=ma
or$F = m\frac{\partial^2 x}{\partial t^2}$
Now x=3t +4t2+5t
$v = \frac{\mathrm{dx} }{\mathrm{d} t}$
v= 3+8t+15t2
$a = \frac{\mathrm{dv} }{\mathrm{d} t}$
a=8+30t
Now a at 2 sec will be 68
so force acting on the object will be ma =136N