Question

What is the speed (approximately) of a 2.5-kilogram mass after it has fallen freely from rest through a distance of 12 meters?

Answer 1

15.3 m/s

Explanation:1) Find the gravitational potential energy using the equation :

`PE_g=mgh`

`PE_g=2.5(12)(9.8)\\PE_g=294`

2) Then use the equation for kinetic energy to solve for the velocity:

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

`294=(1)/(2)(2.5)(v^2)\\235.2=v^2\\√(235.2) =v\\15.3 m/s=v`