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A moving particle is acted upon by several forces `F_(1),F_(2),F_(3)`….etc. One of the force is chosen sat `F_(2)` the which of the following statement about `F_(2)` will be true.A. Work done by `F_(2)` will be negative if speed of the particle decreasesB. Work done by `F_(2)` will be positive if speed of the particle increasesC. Work done by `F_(2)` will be equal to the work done by other forces if speed of the particle does not changeD. If `F_(2)` is a conservative force, then work done by all other forces will be equal to change in potential energy due to force `F_(2)` when speed remains constant. |
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Answer» Correct Answer - D By work energy theorem `W_(F_(2))+W_("other") = Delta K` `rArr W_(F_(2)) = Delta K - W_("other")` So A & B are wrong If speed do not change `Delta K =0` then `W_(F2)=-W_("other")`...(1) So `W_(F_(2))ne W_("other")` If `F_(2)` is conservative force then `Delta U = -W_(F_(2)) = W_("other") ("from" (1)` |
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