Could someone help me with this,please?

Question

A child of mass (m = 47.4 kg) is released from rest at the top of a water slide at a height 6.3 m above the bottom of the slide. If she reached the bottom with a speed of 19.7 m/s. The work done (in J) by friction on the child is:

None

-6211.53

12183.93

-12183.93

6211.53

Answer 1

Without friction E_K at end of slide = E_P at top of the slide. This means that E_K (ideal) = mgh

Work of friction = E_K(ideal) - E_K(actual)

The actual E_k = 1/2 mv² for the v given.