| Exam Board | Edexcel |
|---|---|
| Module | M2 (Mechanics 2) |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Power and driving force |
| Type | Find power at constant speed |
| Difficulty | Moderate -0.8 This is a straightforward two-part question requiring basic conversions and direct application of standard formulas (momentum = mv and Power = Fv). Part (a) is pure substitution with unit conversion, and part (b) uses the standard result that at constant speed, driving force equals resistance, making it a simple calculation with no problem-solving insight required. |
| Spec | 6.02l Power and velocity: P = Fv6.03a Linear momentum: p = mv |
| Answer | Marks | Guidance |
|---|---|---|
| (a) \(5\,000\,000 \times (15\,000 + 3600) = 2.08 \times 10^7\) Ns or kg m s\(^{-1}\) | M1 A1 A1 | |
| (b) \(P = 4000 \times (150 + 36) = 16.7\) kW | M1 A1 A1 | Total: 6 marks |
**(a)** $5\,000\,000 \times (15\,000 + 3600) = 2.08 \times 10^7$ Ns or kg m s$^{-1}$ | M1 A1 A1 |
**(b)** $P = 4000 \times (150 + 36) = 16.7$ kW | M1 A1 A1 | Total: 6 marks\begin{enumerate}
\item A ship, of mass 5000 tonnes, is moving through the sea at a constant speed of $15 \mathrm {~km} \mathrm {~h} ^ { - 1 }$.\\
(a) Calculate the momentum of the ship, in the form $a \times 10 ^ { n }$, where $0 \leq a < 10$ and $n$ is an integer. State the units of your answer.
\end{enumerate}
Given that there is a constant force of magnitude 4000 N acting against the ship due to air and water resistances,\\
(b) find the rate, in kW , at which the ship's engines are working.\\
\hfill \mbox{\textit{Edexcel M2 Q1 [6]}}