Work energy principle and power

[Shah 72]

A child of mass 40kg slides down a playground slide. The child starts from rest at the top of the slide, 2m above the ground. At the bottom of the slide it's slope levels off.
a) Find the child's loss of GPE
I got the ans 800J
there is a constant resistance of 112N throughout
b) find the distance the child has traveled when she comes to rest.
Using work energy principle
Increase in KE =0J
Increase in GPE= -800J
Work done against resistance = -112SJ
So I get S= 7.14m
The slide is inclined at an angle of 30 degree to the horizontal.
C) Find the distance the child travels on the level part of the slide.
I don't understand this part.
Increase in KE= 0J
Increase in GPE= 0- 40×10sin30×2= -400J
Work done by gravity= F×S
I don't understand how to solve further. Pls help

 

[Shah 72]

A child of mass 40kg slides down a playground slide. The child starts from rest at the top of the slide, 2m above the ground. At the bottom of the slide it's slope levels off.
a) Find the child's loss of GPE
I got the ans 800J
there is a constant resistance of 112N throughout
b) find the distance the child has traveled when she comes to rest.
Using work energy principle
Increase in KE =0J
Increase in GPE= -800J
Work done against resistance = -112SJ
So I get S= 7.14m
The slide is inclined at an angle of 30 degree to the horizontal.
C) Find the distance the child travels on the level part of the slide.
I don't understand this part.
Increase in KE= 0J
Increase in GPE= 0- 40×10sin30×2= -400J
Work done by gravity= F×S
I don't understand how to solve further. Pls help
I think I did mistake while calculating Increase in GPE, it will be -800J
Work done by gravity = 200 SJ
So I get S= 4m
I subtract from full length 7.14-4= 3.14m