Arun
Last Activity: 7 Years ago
Dear Student
If angle of inclination is θ, then the acceleration with which the block slides on the incline is g sin 
.
Given that the block is taking a time t/2 and when it is left freely falling from the same height, then the block falls with an acceleration g, at this time it is taking a time t. therefore
S = u* t + (1/2)*g *t^2
h = 0 – (1/2)*g sin
* t^2
t^2 = 2 h/ g sin
and
h sin
= (1/2)*g *(t/2)^2
t^2 = 8 h sin
/ g
Now
8 h sin
/ g = 2 h/ g sin
sin
2 = ¼
sin
= ½
= 30 degree
Regards
Arun (askIITians forum expert)
