An express train is moving with a velocity $\mathbf { V } _ { 1 }$ Its driver finds another train is moving on the same track in the same direction with velocity $v _ { 2 }$ s. To escape collision. driver applies retardation a on the train. The minimum time of escaping collision will be ;

The moment P (in $kg\, ms^{-1}$) of a particle is varying with time t (in second) as $p=2+3t^2$. The force acting on the particle at $t=3s$ will be ;

A car running with a velocity 72 kmph on a level road, is stopped after travelling a distance of 30 m after disengaging its engine $\left( g={ 10ms }^{ -2 } \right)$. The coefficient of friction between ;& ;the road and the tyres is.

16 kg ভরের একটি বোমা বিস্ফোরিত হয়ে 4 & 12 kg এর দুটি খন্ড হলো। 12kg এর বেগ 4ms^-1 হলে অন্য টুকরাটির গতিশক্তি কত?

A rubber ball of mass 50$\mathrm { g }$ falls from a height of $\mathrm { m }$ and rebounds to a height of .5$\mathrm { m }$ . The impulse between the ball and the ground if the time during which they are in contact was $0,1$ sec is