In a children's park, there si a slide which has a total length of 10 and a height of 8.0 m figure. Vertical ladder are provided to reach the top. A boy weighting 200 N climbs up the ladder to the top of the slide and slides down to the ground. The averages friction offered by the slide is three tenth of his weight. Find a. the work done by the ladder on the boy as he goes up. b. the work done by the slide on the boy as he comes down. Neglect any work done by forces inside the body of the boy.

Answer

A, B, C

Explanation

`l=10m, h=8m, mg=200N`
F=200xx(3/10)=60N`
c. Work done by the ladder on the boy is zero.
When the boy is going up because the work is done by the himself.
b.work done against frictioN/Al force,
`W=murS=fl=(-60)xx10`
c. work done by the force insiede the boy is
`W_b=(mgsintheta)xx10`
`=20xx(8/10)`
`=1600J`