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

Answer:

15.3 m/s

Step-by-step 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:

     $KE=\frac{1}{2} mv^{2}$

     $294=\frac{1}{2}(2.5)(v^2)\\235.2=v^2\\\sqrt{235.2} =v\\15.3 m/s=v$