Moderate -0.3 This is a standard direct collision problem requiring conservation of momentum and the elastic collision condition (e = 1 or conservation of kinetic energy). It involves straightforward algebraic manipulation of two simultaneous equations with given masses and initial velocities. While it requires multiple steps, it's a textbook exercise with no novel insight needed, making it slightly easier than average.
2 Two smooth spheres \(A\) and \(B\), of equal radius and of masses 0.2 kg and 0.1 kg respectively, are free to move on a smooth horizontal table. \(A\) is moving with speed \(4 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) when it collides directly with \(B\), which is stationary. The collision is perfectly elastic. Calculate the speed of \(A\) after the impact. [4]
2 Two smooth spheres $A$ and $B$, of equal radius and of masses 0.2 kg and 0.1 kg respectively, are free to move on a smooth horizontal table. $A$ is moving with speed $4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ when it collides directly with $B$, which is stationary. The collision is perfectly elastic. Calculate the speed of $A$ after the impact. [4]
\hfill \mbox{\textit{OCR M2 2007 Q2 [4]}}