Linear and Rotational Motion Question (really struggling)

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The discussion focuses on calculating the pulling force, work done, and average power required to accelerate a 60kg load vertically using a rope and pulley system. The user initially calculated the force as F=60(9.81-6)=228.6N but did not include the friction resistance of 50N. The correct approach involves using F=ma, incorporating all forces, including friction, to determine the pulling force accurately. The work done is calculated as W.D.=(Force + Friction) x Distance, leading to a total work done of 1671.6J.

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Dan_fitz91HNC
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Linear and Rotational Motion


A load of mass 60kg is hoisted vertically by means of a light rope running over a pulley and is accelerated from 3 to 6m/s while traveling through a distance of 6 meter. If the resistance due to friction is 50N determine

A) The pulling force in the rope
B) The work done
C) Average power required to accelerate this load



So far all i have is
F=Mg-Ma=M(g-a)
Do i need to include my 50N friction resistance?

i have F=60(9.81-6)= 228.6N

For my work done i have
Work done=ForcexDistance?

Which i work out to be W.D.=(228.6+50)x6=1671.6W

For average power i have
Average power=W/t
and intera torque =Ia
However i don't know whaere to substitute in the values

Im really stuuggling with this question and its importan for me to get correct if i want to progress onto the next course. Any hints will be much appreciated.
Thankyou
 
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Hi Dan_fitz91HNC! Welcome to PF :smile:
Dan_fitz91HNC said:
… So far all i have is
F=Mg-Ma=M(g-a)
Do i need to include my 50N friction resistance?

i have F=60(9.81-6)= 228.6N

(where did the 6 come from? :confused:)

Sorry, but you need to be more systematic. :redface:

First, find the acceleration, using one of the standard constant acceleration formulas.

Then you can use F = ma (and yes, you have to include all the forces in F). :wink:

What do you get? :smile:
 

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