Question

At the top of a hill that is 4.37 meters high, a 70 kg skate boarder has 3000 1 point
joules of potential energy. What is his speed at the bottom of the hill where
his potential energy is zero?

Answer 1

Answer:

9.26m/s

Explanation:

Given parameters:

Height of the hill  = 4.37m

Mass of skate boarder = 70kg

Potential energy  = 3000J

Unknown:

Speed at the bottom of the hill  = ?

Solution:

At the bottom of the hill, the total potential energy is the same as the kinetic energy.

          Potential energy  = Kinetic energy

                  mgh  =  $\frac{1}{2}$mv²  

                       2mgh  = mv²

                           v² = 2gh

                           v = √2gh

 g is the acceleration due to gravity

h is the height

                     v  = √2 x 9.8 x 4.37  = 9.26m/s