A ball is dropped from the top of a building. The ball takes 0.5sec to fall past the 3m height of a window some distance from the top of the building. If the speed of the ball at the top and the bottom is VT and VB, the establish a relationship between vb and vt take (g = 9.8m/s).
Here using v=u+at , where the symbols have their usual meanings,
We have:
v=VB,
u=VT ,
a= -9.8 m/s2 ,
t= 0.5 sec,
After putting in equation we get
VT – VB = 4.9 m/s
Now using
v2−u2=2as
Or,
VB2 – VT2= −2×9.8×3
= -58.8
Or we can write
(VB-VT)(VB+ VT) = -58.8 m/s
putting the value of VT – VB = 4.9 m/s we get
VB + VT = 12 m/s