Solving a Physics Problem: Forces, Acceleration, and Work

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SUMMARY

The discussion focuses on solving a physics problem involving forces, acceleration, and work related to a child pulling a sled with a dog. The child exerts a force of 55N at a 20-degree angle, with a coefficient of friction of 0.22. The normal force calculated is 8.563N, leading to an acceleration of 0.428m/s² for the system. The work done by the child over a distance of 7m is determined to be 59.94J.

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A child pulls a 15kg sled containing a 5kg dog along a straight path on a horizontal surface. He exerts a force of a 55N on the sled at an angle of 20 degree above the horizontal. The coefficient of friction between the sled and the surface is 0.22 .
Find:a) normal force of the surface on the system , b) the acceleration of system, c) the work done by the child as the system move 7m.
This is how i approach them

a)normal force = Force of the child exert - Force of friction
55cos20 - .22( (15+5)9.8 ) = 8.563 N

b)normal force= ma
8.563N = ( 15+5 )a
a=.428m/s^2

c)W=Fd W=8.563(7)= 59.94J

give me suggest if I am make a mistake
 
Last edited:
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What do you understand "normal" to mean when talking about surfaces?
 

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