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logglypop
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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
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