| Exam Board | Edexcel |
|---|---|
| Module | M2 (Mechanics 2) |
| Year | 2021 |
| Session | October |
| Marks | 14 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Work done and energy |
| Type | Projectile energy - finding speed or height |
| Difficulty | Standard +0.3 This is a straightforward M2 question combining energy conservation with projectile motion. Part (a) is direct application of energy conservation (a standard technique), part (b) requires basic SUVAT with horizontal motion, and part (c) needs finding when speed equals 8 m/s using standard kinematics. All parts follow well-practiced procedures with no novel insight required, making it slightly easier than average. |
| Spec | 3.02h Motion under gravity: vector form3.02i Projectile motion: constant acceleration model6.02d Mechanical energy: KE and PE concepts6.02e Calculate KE and PE: using formulae6.02i Conservation of energy: mechanical energy principle |
8.
\begin{figure}[h]
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\includegraphics[alt={},max width=\textwidth]{80dceee7-2eea-4082-ad20-7b3fe4e8bb25-24_470_824_214_561}
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\caption{Figure 4}
\end{center}
\end{figure}
The fixed point $A$ is $h$ metres vertically above the point $O$ that is on horizontal ground. At time $t = 0$, a particle $P$ is projected from $A$ with speed $10 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. The particle moves freely under gravity. At time $t = 2.5$ seconds, $P$ strikes the ground at the point $B$. At the instant when $P$ strikes the ground, the speed of $P$ is $18 \mathrm {~ms} ^ { - 1 }$, as shown in Figure 4.
\begin{enumerate}[label=(\alph*)]
\item By considering energy, find the value of $h$.
\item Find the distance $O B$.
As $P$ moves from $A$ to $B$, the speed of $P$ is less than or equal to $8 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ for $T$ seconds.
\item Find the value of $T$
\end{enumerate}
\hfill \mbox{\textit{Edexcel M2 2021 Q8 [14]}}