A driver of a train travelling at $40\, m s ^{-1}$ applies the breaks as a train enters a station. The train slows down at a rate of $2\, m s ^{-2} .$ The platform is $400\, m$ long. Will the train stop in time ?
Given $u=40 m s ^{-1}, v=0, a=-2 m s ^{-2}, S =?$
Using equation, we have
$0=(40)^{2}+2(-2) S$
or $\quad 4 S=1600$ or $S=400 m$.
Thus, the train stops in $400 m$. Since the platform is $400 m$ long, therefore, the train just stops in time.
The brakes applied to a car produce an acceleration of $6\, m s ^{-2}$ in the opposite direction of motion. If the car takes $2\, s$ to stop after the application of the brakes, calculate the distance it travels during this time.
The nelocitu$-$time graph of a body is as shown. What tupe of motion does the body posses ?
If the acceleration of the particle is constant in magnitude but not in direction, what type of path does the particle follow ?
An object starting from rest travels $20\, m$ in first $2\,\sec $ and $160\, m$ in next $4\,\sec $. What will be the velocity after $7\,\sec $ from the start ?
If the displacement of a body is proportional to the square of the time elapsed, what type of motion does the body possess ?