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Grade 12Mechanics

The two blocks of masses m1=4kg and m2=2kg are connected to the ends if the strring which are moving over the pulley the total downward force is nearly equal to?

Profile image of Rasika
7 Years agoGrade 12
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1 Answer

Profile image of Agrata Singh
7 Years ago
The total downward force is the vector sum of all the forces externally acting on system
In this the forces acting are wt. of the twoo blocks and tension in string
However tension in the string is an internal force and internal forces always exist in pair. If The block is pulled by the pulley by T amount of tension force then pulley is also pulled by the block by same T force. Hence being opposite in direction their magnitudes are cancelled while taking the resultant.
Also 4kg block being heavier will move down and the 2 kg moves up. Gravity applies force downward. So we can say that 4 kg block prefers the downward force while 2 kg opposes it.
Therefore net downward force is 4g-2g=2g