At time t i , the kinetic energy of a particle is32.0 J and the potential energy
ID: 1668574 • Letter: A
Question
At time ti, the kinetic energy of a particle is32.0 J and the potential energy of thesystem to which it belongs is 12.0 J. Atsome later time tf, the kinetic energy of theparticle is 16.0 J. (a) If only conservative forces act on theparticle, what are the potential energy and the total energy attime tf?(b) If the potential energy of the system at timetf is 23.0 J, arethere any nonconservative forces acting on theparticle? Yes. The loss in potential energy andthe gain in kinetic energy of the system are notequal. No. The loss in potential energy and thegain in kinetic energy of the system areequal. No. The gain in potential energy and theloss in kinetic energy of the system are equal. Yes.The gain in potential energy and the loss in kinetic energy of thesystem are not equal. (a) If only conservative forces act on theparticle, what are the potential energy and the total energy attime tf?
(b) If the potential energy of the system at timetf is 23.0 J, arethere any nonconservative forces acting on theparticle? Yes. The loss in potential energy andthe gain in kinetic energy of the system are notequal. No. The loss in potential energy and thegain in kinetic energy of the system areequal. No. The gain in potential energy and theloss in kinetic energy of the system are equal. Yes.The gain in potential energy and the loss in kinetic energy of thesystem are not equal.
Explanation / Answer
(a) Total E = 32 + 12 = 44 J at time ti At time tf, Kf = 16.0 J Uf = E-Kf = 44- 16.0 = 28 J (b)If at tf, Kf = 16.0 J but Uf = 23.0J Loss in K = 32.0 - 16.0 = 16.0J Gain in U = 23.0 - 12.0 = 11.0J These are not equal. Hence some non-conservative forces areacting. Last choice of options is correct. Yes. The gain in potential energy of the system and the lossin Kinetic energy of the system are not equal.Related Questions
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