AQA M1 2005 January — Question 8 16 marks

Exam BoardAQA
ModuleM1 (Mechanics 1)
Year2005
SessionJanuary
Marks16
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProjectiles
TypeBasic trajectory calculations
DifficultyModerate -0.8 This is a straightforward projectile motion question requiring standard SUVAT equations with vertical/horizontal components. Part (a) is recall, parts (b) and (c) involve routine calculations (time to max height using v=u+at, then using s=ut+½at², and finally horizontal distance). The 'show that' in (b)(ii) provides the answer, reducing difficulty. No novel problem-solving or geometric insight required—purely algorithmic application of memorized formulas.
Spec3.02d Constant acceleration: SUVAT formulae3.02h Motion under gravity: vector form3.02i Projectile motion: constant acceleration model

8 A football is placed on a horizontal surface. It is then kicked, so that it has an initial velocity of \(12 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) at an angle of \(40 ^ { \circ }\) above the horizontal.
  1. State two modelling assumptions that it would be appropriate to make when considering the motion of the football.
    1. Find the time that it takes for the ball to reach its maximum height.
    2. Hence show that the maximum height of the ball is 3.04 metres, correct to three significant figures.
  2. After the ball has reached its maximum height, it hits the bar of a goal at a height of 2.44 metres. Find the horizontal distance of the goal from the point where the ball was kicked.

Question 8:
Part (a)
AnswerMarks Guidance
Ball is a particleB1 One appropriate assumption
No air resistanceB1 (2) Second appropriate assumption
Part (b)(i)
AnswerMarks Guidance
\(0 = 12\sin40° - 9.8t\)M1, A1 Equation to find time at maximum height; Correct equation
\(t = \frac{12\sin40°}{9.8} = 0.787 \text{ s}\)M1, A1 (4) Solving for \(t\); Correct time
Part (b)(ii)
AnswerMarks Guidance
\(h = 12\sin40°\times0.7871 - 4.9\times0.7871^2\)M1 Substituting time into expression for height
\(= 3.04 \text{ m}\)A1, A1 (3) Correct expression; AG correct height from correct working
Part (c)
AnswerMarks Guidance
\(2.44 = 12\sin40°t - 4.9t^2\)M1 Equation for time based on height being 2.44
\(4.9t^2 - 12\sin40°t + 2.44 = 0\)A1, A1 Correct LHS; Correct RHS
\(t = 0.4385 \text{ or } 1.136\)m1, A1 Solving quadratic; Correct time(s)
\(s = 12\cos40°\times1.136 = 10.4 \text{ m}\)M1, A1 (7) Substituting larger time into horizontal displacement expression; Correct distance
## Question 8:

### Part (a)
Ball is a particle | B1 | One appropriate assumption
No air resistance | B1 (2) | Second appropriate assumption

### Part (b)(i)
$0 = 12\sin40° - 9.8t$ | M1, A1 | Equation to find time at maximum height; Correct equation
$t = \frac{12\sin40°}{9.8} = 0.787 \text{ s}$ | M1, A1 (4) | Solving for $t$; Correct time

### Part (b)(ii)
$h = 12\sin40°\times0.7871 - 4.9\times0.7871^2$ | M1 | Substituting time into expression for height
$= 3.04 \text{ m}$ | A1, A1 (3) | Correct expression; AG correct height from correct working

### Part (c)
$2.44 = 12\sin40°t - 4.9t^2$ | M1 | Equation for time based on height being 2.44
$4.9t^2 - 12\sin40°t + 2.44 = 0$ | A1, A1 | Correct LHS; Correct RHS
$t = 0.4385 \text{ or } 1.136$ | m1, A1 | Solving quadratic; Correct time(s)
$s = 12\cos40°\times1.136 = 10.4 \text{ m}$ | M1, A1 (7) | Substituting larger time into horizontal displacement expression; Correct distance
8 A football is placed on a horizontal surface. It is then kicked, so that it has an initial velocity of $12 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ at an angle of $40 ^ { \circ }$ above the horizontal.
\begin{enumerate}[label=(\alph*)]
\item State two modelling assumptions that it would be appropriate to make when considering the motion of the football.
\item \begin{enumerate}[label=(\roman*)]
\item Find the time that it takes for the ball to reach its maximum height.
\item Hence show that the maximum height of the ball is 3.04 metres, correct to three significant figures.
\end{enumerate}\item After the ball has reached its maximum height, it hits the bar of a goal at a height of 2.44 metres. Find the horizontal distance of the goal from the point where the ball was kicked.
\end{enumerate}

\hfill \mbox{\textit{AQA M1 2005 Q8 [16]}}