A BULLET STOPS AFTER TRAVELLING A DISTANCE OF XM UNDER THE ACTION OF A UNIFORM RETARDING FORCE .HOW FAR WILL IT GO BEFORE BEING STOPPED BY THE SAME FORCE IF ITS VELOCITY IS DOUBLED?
Let the initial velocity be ‘u’
It travels a distance ‘x’ before coming to rest.
Using,
v2 = u2 + 2ax
=> 0 = u2 + 2ax
=> a = -u2/(2x)
If the initial velocity is ‘2u’ then,
v2 = (2u)2 + 2a(x/)
=> 0 = 4u2 – [2u2/(2x)](x/)
=> x/ = 4x
Thus, when the initial velocity is double the distance traveled before coming to rest is ‘4x’.