Asked by jain.pradeep | 27th Apr, 2019, 10:51: AM

Expert Answer:

qn.18 :-  net force = mass × acceleration.  but acceleration ( g sinθ ) along the direction  is constant throughout the motion.
                  Hence graph-E  represents the net force.
qn.19 :-  speed of the block  = u - gsinθ t  , which is linearly decreasing during upward motion and linearly increasing during downward motion
                  Hence graph-A represents the speed of block
qn. 20 :-  potential energy is proportional to vertical distance h. Vertical distance h is given by,  h = u sinθ t - (1/2) g sinθ t2  
                Hence potential energy is a quadratic function and initially increasing while going up then decreasing while coming down.
                 Graph-D represents the potential energy.
qn. 21 :- since total mechanical energy is constant throughout the motion, graph-E represents the total mechanical energy

Answered by Thiyagarajan K | 27th Apr, 2019, 04:58: PM

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