Question

1. A 65 kg student, starting from rest, slides down an 16.2 m high water slide. On the way down, friction does 5700 J of work on him. How fast is he going at the bottom of the slide

Answer 1

11.94

Step-by-step explanation:

Remark

Find the Potential Energy at the top.

Givens

m = 65 kg

h = 16.2 m

g = 9.81

PE = 65 * 9.81 * 16.2

PE = 10329.93

The tricky part is what do you do about Friction?

Formula

PE = Friction + KE

Solution

PE = 10329.93 Joules

Friction = 5700 Joules

Find the KE

10329.93 = 5700 + KE

KE = 10329.93 - 5700

KE = 4629.93

Find V from the KE formula

KE = 4629.93

m = 65

KE = 1/2 m v^2

KE = 1/2 65 v^2

4629.93 = 1/2 65 v^2

v^2 = 142.46

v = √142.46

v = 11.94