Question

If a rock is thrown 0.8 meters into the air, How fast was it thrown

Answer 1

Speed, s = 3.95 m/s

Step-by-step explanation:

It is given that, a rock is thrown 0.8 meters into the air. We have to find the velocity with which it is thrown.

Using conservation of mechanical energy as :

`K_i+P_i=K_f+P_f`

Initial potential energy at the ground is 0 and at maximum height the final kinetic energy is 0.

So,

`(1)/(2)mv^2=mgh`

`v=√(2gh)`

putting g = 9.8 m/s² and h = 0.8 m

`v=√(2* 9.8* 0.8)`

v = 3.95 m/s

Hence, it was thrown with a speed of 3.95 m/s