Physics

Problem

Two trolleys

A

and

B

move on a smooth horizontal track in the same straight line. Trolley

A

has mass

1.5\,\text{kg}

and speed

4\,\text{m}\,\text{s}^{-1}

. Trolley

B

has mass

3.0\,\text{kg}

. a. (i) The two trolleys are adjusted so that their kinetic energies are equal. Calculate the required speed of trolley

B

. b. (ii) For the above condition of equal kinetic energies, determine the magnitudes of the momenta of

A

and

B

. c. (iii) Explain why the two trolleys have different momenta even though their kinetic energies are the same. d. (iv) If, instead, the magnitudes of their momenta were made equal, would their kinetic energies be the same? Give a reasoned answer without numerical calculation.

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