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A body of mass 1kg is taken from infinit...

A body of mass `1kg` is taken from infinity to a point P. When the body reaches that point, it has a speed of `2ms^-1`. The work done by the conservative force is `-5J`. Which of the following is true (assuming non-conservative and pseudo-forces to be absent).

A

Work done by the applied force is +7 J.

B

The total energy possessed by the body at P is +5 J.

C

The potential energy possessed by the body at P is `+5` J.

D

Work done by all forces together is equal to the change in kinetic energy.

Text Solution

Verified by Experts

The correct Answer is:
A, B, C, D
Change in kinetic energy,
`Delta KE= (1)/(2) mv^(2) = (1)/(2) xx 1 xx 2^(2) = 2 J`
`therefore W_("cos") =-Delta U =5 J rArr Delta U= 5 J`.
`therefore W_("ext") = Delta U + Delta KE= 5+2 =7 J`.
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