Question

A student leans over the side of a building and throws a 150g of stone vertically upward with a initial velocity 12 m/s. He find that it takes exactly 8.2 seconds for the stone to reach the foot of the building. calculate the height of the building​

Answer 1

Initial Velocity u=40

Fianl velocity v=0

Height, s=?

By third equation of motion

v

2

−u

2

=2gs

0−40

2

=−2×10×s

s=

20

160

⇒s=80m/s

Toatl distance travelled by stone = upward distance + downwars distance =2×s=160m

Total Diaplacement =0, Since the initial and final point is same.