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A body initially at rest is acted upon by a constantforce. The rate of change of its kinetic energyvaries |
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Answer» Basically the request is for deriving the expression for Kinetic Energy. It is given that mass 'm' at rest whose velocity changes to 'v' in 't' seconds . It means there is acceleration and hence a force F is acting on the body. First we will compute the acceleration = a from the relation V= U+at In our case U the initial velocity = 0 ∴ V = at ⇒ a = V/t Force = m*a = m*V/t Distance moved is (1/2)*a*t² = (1/2)*(V/t)*t² = Vt/2 Work done on the body : (which is stored as Kinetic energy in it) = KE = F*s = (m*a)*s = m*(V/t)* (Vt/2) = (1/2)*m*V² |
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