Moderate -0.8 This is a straightforward application of conservation of momentum with one unknown. Students set up the momentum equation before and after collision, substitute given values, and solve a simple linear equation for m. It requires only basic algebraic manipulation and direct recall of momentum principles, making it easier than average.
1 Each of two wagons has an unloaded mass of 1200 kg . One of the wagons carries a load of mass \(m \mathrm {~kg}\) and the other wagon is unloaded. The wagons are moving towards each other on the same rails, each with speed \(3 \mathrm {~m} \mathrm {~s} ^ { - 1 }\), when they collide. Immediately after the collision the loaded wagon is at rest and the speed of the unloaded wagon is \(5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). Find the value of \(m\).
1 Each of two wagons has an unloaded mass of 1200 kg . One of the wagons carries a load of mass $m \mathrm {~kg}$ and the other wagon is unloaded. The wagons are moving towards each other on the same rails, each with speed $3 \mathrm {~m} \mathrm {~s} ^ { - 1 }$, when they collide. Immediately after the collision the loaded wagon is at rest and the speed of the unloaded wagon is $5 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. Find the value of $m$.
\hfill \mbox{\textit{OCR M1 2006 Q1 [5]}}