Edexcel M1 — Question 1 7 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicForces, equilibrium and resultants
TypeForces in vector form: resultant and acceleration
DifficultyModerate -0.8 This is a straightforward M1 kinematics question requiring only direct application of standard formulae (v = u + at and F = ma) with vector notation. All three parts involve routine calculations with no problem-solving insight needed, making it easier than average for A-level.
Spec1.10h Vectors in kinematics: uniform acceleration in vector form3.03c Newton's second law: F=ma one dimension

A particle \(P\), of mass \(2.5\) kg, initially at rest at the point \(O\), moves on a smooth horizontal surface with constant acceleration \((\mathbf{i} + 2\mathbf{j})\) ms\(^{-2}\), where \(\mathbf{i}\) and \(\mathbf{j}\) are unit vectors in the directions due East and due North respectively. Find
  1. the velocity vector of \(P\) at time \(t\) seconds after it leaves \(O\), \hfill [2 marks]
  2. the magnitude and direction of the velocity of \(P\) when \(t = 7\), \hfill [3 marks]
  3. the magnitude, in N, of the force acting on \(P\). \hfill [2 marks]

AnswerMarks Guidance
(a) \((i + 2j)\) ms\(^{-1}\)M1 A1; M1 A1
(b) \(\sqrt{(7^2 + 14^2)} = 7\sqrt{5}\) or \(15.7\) ms\(^{-1}\)A1; M1 A1
on bearing \(\tan^{-1} 0.5 = 026.6°\)
(c) \(2.5\sqrt{5} = 5.59\) NA1; M1 A1 Total: 7 marks
**(a)** $(i + 2j)$ ms$^{-1}$ | M1 A1; M1 A1 |

**(b)** $\sqrt{(7^2 + 14^2)} = 7\sqrt{5}$ or $15.7$ ms$^{-1}$ | A1; M1 A1 |

on bearing $\tan^{-1} 0.5 = 026.6°$ | |

**(c)** $2.5\sqrt{5} = 5.59$ N | A1; M1 A1 | **Total: 7 marks**
A particle $P$, of mass $2.5$ kg, initially at rest at the point $O$, moves on a smooth horizontal surface with constant acceleration $(\mathbf{i} + 2\mathbf{j})$ ms$^{-2}$, where $\mathbf{i}$ and $\mathbf{j}$ are unit vectors in the directions due East and due North respectively. Find
\begin{enumerate}[label=(\alph*)]
\item the velocity vector of $P$ at time $t$ seconds after it leaves $O$, \hfill [2 marks]
\item the magnitude and direction of the velocity of $P$ when $t = 7$, \hfill [3 marks]
\item the magnitude, in N, of the force acting on $P$. \hfill [2 marks]
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1  Q1 [7]}}