# A lift whose cage is 3 meter high is moving up with an acceleration of 2 meter per second square . A piece of stone is dropped from the top of the cage of the lift when it's velocity is 8 meter per second . If gram = 10 meter per second second square , then the stone will reach the floor of the lift after

dhruba
17 Points
one year ago
listing the facts …
set the point from where the ball was thrown as origin and follow sign convention
initial velocity of the ball(u)= +8 m/s(not -8m/s)
height to be covered(s)=-3m
acceleration is only due to gravity(g)_=-10 m/s^2

using equation $x=ut+1/2at^2$  we get  -3=8(t)+1/2 (-10)(t^2)   solving u get t=3/5 sec or 1 sec

dhruba
17 Points
one year ago
saying position would be more accurate wherever i told height ….........thats why we could give the sign negativ eor positive so please do the corrcetion