- #1
anna sung
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Homework Statement
A 15 kg child slides, from rest, down a playground slide tht is 4.0 m long, as shown in the figure. The slide makes a 40 degrees angle with the horizontal. The child's speed at the bottom is 3.2 m/s. What was teh force of friction that the sldie was exerting on the child?
Ok. The answer in the texbook says 75N.
Homework Equations
Wnc=Efinal-Einitial
The Attempt at a Solution
Here is my WROng attempt
work=Kinetic Energy 2 - Kinetic Energy 1
work = 1/2 m (V2squared - v1squared)
w=1/2 (15 kg) (3.2 m/s squared - 0)
w=7.5 (10.24 m/s)
w=76.8 J
then I..
Work=force (distance) (cos40)
f= w/d (cos 40)
f=76.8 J / 4.0 (cos 40)
f=14.7 N
could you please actually plug in the numbers and show me how to get to the answer?
rather than giving just the steps? please thank you!