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podryga [215]
3 years ago
9

A steel playground slide is 5.25 m long and is raised 2.75 m on one end. A 45.0 kg child slides down from the top starting at re

st. The final speed of the child at the bottom is 6.81 m/s. Find the average force of friction between the child and the slide.
Physics
1 answer:
Temka [501]3 years ago
8 0

Answer:

F=32.24N

Explanation:

From the question we are told that:

Height h= 2.75 m

Lengthl = 5.25 m

Mass m=45kg

Final speed v_f=6.81

Generally the equation for Potential Energy P.E is mathematically given by

P.E=mgh

Therefore

Initial potential energy

P.E_1=45*9.8*2.75 \\\\P.E_1= 1212.75 J

Generally the equation for Kinetic Energy K.E is mathematically given by

K.E=0.5mv^2

Therefore

Final kinetic energy

K.E_2= 1/2*45*6.81*6.81 \\\\K.E_2= 1043.46J

Generally the equation for Work_done is mathematically given by

W=P.E_1-K.E_2\\\\W=169.3

Therefore

F=\frac{W}{d}\\\\F=\frac{169.3}{5.25}

F=32.24N

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{v}^{2} = {u}^{2} + 2gh
Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
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Substitute for the values and you should have something like this
{7}^{2} = {0}^{2} + 2 \times 10 \times h
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Shown by explanation;

Explanation:

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