Edexcel M1 2024 June — Question 5 14 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2024
SessionJune
Marks14
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSUVAT in 2D & Gravity
TypeVertical motion with resistance force
DifficultyStandard +0.3 This is a standard M1 two-stage motion problem requiring SUVAT equations for free fall, then Newton's second law with resistance force. All steps are routine: (a) uses s=ut+½at², (b) requires finding acceleration with resistance then using v²=u²+2as, (c) adds times from both phases, (d) is a standard sketch. Slightly easier than average due to straightforward application of well-practiced techniques with no conceptual surprises.
Spec3.02b Kinematic graphs: displacement-time and velocity-time3.02c Interpret kinematic graphs: gradient and area3.02d Constant acceleration: SUVAT formulae3.02h Motion under gravity: vector form

  1. A parachute is used to deliver a box of supplies. The parachute is attached to the box.
  • the parachute and box are dropped from rest from a helicopter that is hovering at a height of 520 m above the ground
  • the parachute and box fall vertically and freely under gravity for 5 seconds, then the parachute opens
  • from the instant the parachute opens, it provides a resistance to motion of magnitude 3200 N
  • the parachute and box continue to fall vertically downwards after the parachute opens
  • the parachute and box are modelled throughout the motion as a particle \(P\) of mass 250 kg
    1. Find the distance fallen by \(P\) in the first 5 seconds.
    2. Find the speed with which \(P\) lands on the ground.
    3. Find the total time from the instant when \(P\) is dropped from the helicopter to the instant when \(P\) lands on the ground.
    4. Sketch a speed-time graph for the motion of \(P\) from the instant when \(P\) is dropped from the helicopter to the instant when \(P\) lands on the ground.
VJYV SIHI NI JIIYM ION OCVayv sthin NI JLIYM ION OAVJYV SIHI NI JAIVM ION OC

Question 5:
Part (a)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(s = \frac{1}{2} \times 9.8 \times 5^2\)M1 Complete method to find the distance
\(= 123\) or \(120\) (m)A1 (2) cao
Part (b)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(v = 9.8 \times 5 = 49\) OR \(v = \sqrt{2 \times 9.8 \times 122.5} = 49\) OR \(122.5 = 5v - \frac{1}{2} \times 9.8 \times 5^2 \Rightarrow v = 49\)B1 B1: 49 or \(-49\); allow \(5g\) or \(-5g\) or \(49^2\) (2401) seen
\(250g - 3200 = \pm 250a\)M1A1 M1: Equation of motion, correct terms, condone sign errors
Correct value for \(a\) (3 or \(-3\))A1 Correct equation (allow \(+\) or \(-\))
\(v^2 = 49^2 - 2 \times 3 \times (520 - 122.5)\)M1 A1ft M1: Complete method to find speed at ground (must have found new \(a\)); M0 if \(u=0\) used
\(v = 4\) (m s\(^{-1}\))A1 (7) cao
Part (c)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(4 = 49 - 3t\) OR \((520-122.5) = \frac{(49+4)}{2}t\) OR \((520-122.5) = 49t - \frac{1}{2} \times 3t^2\) OR \((520-122.5) = 4t + \frac{1}{2} \times 3t^2\)M1
\(t = 15\) (other root \(\frac{53}{3}\) leads to \(v < 0\))A1
Total time \(= 5 + 15 = 20\) (s)A1ft (3)
Part (d)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
Graph: straight line from 49 decreasing to 4, then horizontal line at 4 to \(t = 20\)B1 shape Correct shape
Values 49, 4, 20 marked correctlyB1ft figs (2) ft on their figures
# Question 5:

## Part (a)
| Answer/Working | Marks | Guidance |
|---|---|---|
| $s = \frac{1}{2} \times 9.8 \times 5^2$ | M1 | Complete method to find the distance |
| $= 123$ or $120$ (m) | A1 (2) | cao |

## Part (b)
| Answer/Working | Marks | Guidance |
|---|---|---|
| $v = 9.8 \times 5 = 49$ **OR** $v = \sqrt{2 \times 9.8 \times 122.5} = 49$ **OR** $122.5 = 5v - \frac{1}{2} \times 9.8 \times 5^2 \Rightarrow v = 49$ | B1 | B1: 49 or $-49$; allow $5g$ or $-5g$ or $49^2$ (2401) seen |
| $250g - 3200 = \pm 250a$ | M1A1 | M1: Equation of motion, correct terms, condone sign errors |
| Correct value for $a$ (3 or $-3$) | A1 | Correct equation (allow $+$ or $-$) |
| $v^2 = 49^2 - 2 \times 3 \times (520 - 122.5)$ | M1 A1ft | M1: Complete method to find speed at ground (must have found new $a$); M0 if $u=0$ used |
| $v = 4$ (m s$^{-1}$) | A1 (7) | cao |

## Part (c)
| Answer/Working | Marks | Guidance |
|---|---|---|
| $4 = 49 - 3t$ **OR** $(520-122.5) = \frac{(49+4)}{2}t$ **OR** $(520-122.5) = 49t - \frac{1}{2} \times 3t^2$ **OR** $(520-122.5) = 4t + \frac{1}{2} \times 3t^2$ | M1 | |
| $t = 15$ (other root $\frac{53}{3}$ leads to $v < 0$) | A1 | |
| Total time $= 5 + 15 = 20$ (s) | A1ft (3) | |

## Part (d)
| Answer/Working | Marks | Guidance |
|---|---|---|
| Graph: straight line from 49 decreasing to 4, then horizontal line at 4 to $t = 20$ | B1 shape | Correct shape |
| Values 49, 4, 20 marked correctly | B1ft figs (2) | ft on their figures |
\begin{enumerate}
  \item A parachute is used to deliver a box of supplies. The parachute is attached to the box.
\end{enumerate}

\begin{itemize}
  \item the parachute and box are dropped from rest from a helicopter that is hovering at a height of 520 m above the ground
  \item the parachute and box fall vertically and freely under gravity for 5 seconds, then the parachute opens
  \item from the instant the parachute opens, it provides a resistance to motion of magnitude 3200 N
  \item the parachute and box continue to fall vertically downwards after the parachute opens
  \item the parachute and box are modelled throughout the motion as a particle $P$ of mass 250 kg\\
(a) Find the distance fallen by $P$ in the first 5 seconds.\\
(b) Find the speed with which $P$ lands on the ground.\\
(c) Find the total time from the instant when $P$ is dropped from the helicopter to the instant when $P$ lands on the ground.\\
(d) Sketch a speed-time graph for the motion of $P$ from the instant when $P$ is dropped from the helicopter to the instant when $P$ lands on the ground.
\end{itemize}

\begin{center}
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VJYV SIHI NI JIIYM ION OC & Vayv sthin NI JLIYM ION OA & VJYV SIHI NI JAIVM ION OC \\
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\end{tabular}
\end{center}

\hfill \mbox{\textit{Edexcel M1 2024 Q5 [14]}}