Edexcel M2 — Question 3 7 marks

Exam BoardEdexcel
ModuleM2 (Mechanics 2)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPower and driving force
TypeMaximum speed on incline vs horizontal
DifficultyStandard +0.3 This is a straightforward M2 power question requiring application of P=Fv and resolving forces at constant speed. Part (a) uses standard inclined plane resolution with sin(10°), and part (b) is a direct application of the same power on horizontal ground. The multi-step nature and need to work with power equations elevates it slightly above average, but it follows a standard template with no conceptual surprises.
Spec6.02l Power and velocity: P = Fv6.02m Variable force power: using scalar product

An engine of mass \(20\,000\) kg climbs a hill inclined at \(10°\) to the horizontal. The total non-gravitational resistance to its motion has magnitude \(35\,000\) N and the maximum speed of the engine on the hill is \(15\) ms\(^{-1}\).
  1. Find, in kW, the maximum rate at which the engine can work. [4 marks]
  2. Find the maximum speed of the engine when it is travelling on a horizontal track against the same non-gravitational resistance as before. [3 marks]

AnswerMarks Guidance
(a) \(P = 15(35000 + 20000g\sin 10°) = 1035525.6\) W \(\approx 1040\) kWM1 M1 A1 A1
(b) \(1035525.6 = v \times 35000\)M1 A1
\(v = 29.6\) m/s\(^{-2}\)M1 A1 Total: 7 marks
**(a)** $P = 15(35000 + 20000g\sin 10°) = 1035525.6$ W $\approx 1040$ kW | M1 M1 A1 A1 |

**(b)** $1035525.6 = v \times 35000$ | M1 A1 |
$v = 29.6$ m/s$^{-2}$ | M1 A1 | **Total: 7 marks**
An engine of mass $20\,000$ kg climbs a hill inclined at $10°$ to the horizontal. The total non-gravitational resistance to its motion has magnitude $35\,000$ N and the maximum speed of the engine on the hill is $15$ ms$^{-1}$.

\begin{enumerate}[label=(\alph*)]
\item Find, in kW, the maximum rate at which the engine can work. [4 marks]
\item Find the maximum speed of the engine when it is travelling on a horizontal track against the same non-gravitational resistance as before. [3 marks]
\end{enumerate}

\hfill \mbox{\textit{Edexcel M2  Q3 [7]}}