Question

A body weighing 10 kg falls from a height of 20 m. Calculate the velocity and kinetic energy of the body when falling to the ground

Answer 1

v = 19.8 m/s

KE = 1960.2 J

Step-by-step explanation:

We can calculate the velocity of the body by using the formula:

• 
  `v=√(2gh)`
• since we are given the height, and we know that g = 9.8 m/s².

Plug the known values into the equation.

• 
  `v=√(2\cdot 9.8\cdot 20)`
• 
  `v=√(392)`
• 
  `\displaystyle v=19.8 \ (m)/(s)`

Now we can use the formula for kinetic energy to calculate the kinetic energy of the body:

• 
  `\displaystyle KE = (1)/(2)mv^2`

Plug in 19.8 m/s for v and 10 kg for m.

• 
  `\displaystyle KE =(1)/(2) (10)(19.8)^2`
• 
  `\displaystyle KE=(5)(392.04)`
• 
  `\displaystyle KE = 1960.2 \ J`

The kinetic energy of the body when falling to the ground is 1960.2 Joules.