A student throws a 0.22 kg rock horizontally at 20.0 m/s from 10.0 m above the ground. Find the initial kinetic energy of the rock.

44J

Explanation:

Given parameters:

Mass of rock  = 0.22kg

Initial velocity  = 20m/s

Distance moved  = 10m

Unknown:

Initial kinetic energy of the rock  = ?

Solution:

To solve this problem, we need to understand that kinetic energy is the energy due to the motion of a body.

It is mathematically expressed as;

     Kinetic energy  = m v²

m is the mass

v is the velocity

   Kinetic energy  =   x 0.22 x 20²   = 44J

because growing process had stoped after 4-5 year