CAIE M2 2015 June — Question 2 5 marks

Exam BoardCAIE
ModuleM2 (Mechanics 2)
Year2015
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProjectiles
TypeVelocity direction at specific time/point
DifficultyStandard +0.3 This is a straightforward projectiles question requiring standard resolution of velocity components and use of kinematic equations. Students must find the angle condition tan(45°)=1 relating horizontal and vertical velocities at t=1.5s, solve for V, then calculate displacements using standard formulae. While it involves multiple steps, all techniques are routine M2 material with no novel insight required, making it slightly easier than average.
Spec3.02i Projectile motion: constant acceleration model

2 A particle \(P\) is projected with speed \(V \mathrm {~m} \mathrm {~s} ^ { - 1 }\) at an angle of \(60 ^ { \circ }\) above the horizontal from a point \(O\) on horizontal ground. \(P\) is moving at an angle of \(45 ^ { \circ }\) above the horizontal at the instant 1.5 s after projection.
  1. Find \(V\).
  2. Hence calculate the horizontal and vertical displacements of \(P\) from \(O\) at the instant 1.5 s after projection.

Question 2:
Part (i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
Vert comp vel \(= V\sin60 - 1.5g\)B1
\(V\cos60 = V\sin60 - 1.5g\)M1 \((V\sin60 - 1.5g)/(V\cos60) = \tan45\)
\(V = 41(.0)\)A1 [3 marks]
Part (ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(X\ [= (41\cos60) \times 1.5] = 30.7\) mB1\(\checkmark\) ft candidate value \((41.0) \times 0.75\); Allow 30.8
\(Y\ [=(41\sin60) \times 1.5 - g1.5^2/2] = 42(.0)\) mB1\(\checkmark\) [2 marks] ft candidate value \((41.0) \times 1.3 - 11.25\)
## Question 2:

### Part (i):
| Answer/Working | Mark | Guidance |
|---|---|---|
| Vert comp vel $= V\sin60 - 1.5g$ | B1 | |
| $V\cos60 = V\sin60 - 1.5g$ | M1 | $(V\sin60 - 1.5g)/(V\cos60) = \tan45$ |
| $V = 41(.0)$ | A1 | **[3 marks]** |

### Part (ii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $X\ [= (41\cos60) \times 1.5] = 30.7$ m | B1$\checkmark$ | ft candidate value $(41.0) \times 0.75$; Allow 30.8 |
| $Y\ [=(41\sin60) \times 1.5 - g1.5^2/2] = 42(.0)$ m | B1$\checkmark$ | **[2 marks]** ft candidate value $(41.0) \times 1.3 - 11.25$ |

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2 A particle $P$ is projected with speed $V \mathrm {~m} \mathrm {~s} ^ { - 1 }$ at an angle of $60 ^ { \circ }$ above the horizontal from a point $O$ on horizontal ground. $P$ is moving at an angle of $45 ^ { \circ }$ above the horizontal at the instant 1.5 s after projection.\\
(i) Find $V$.\\
(ii) Hence calculate the horizontal and vertical displacements of $P$ from $O$ at the instant 1.5 s after projection.

\hfill \mbox{\textit{CAIE M2 2015 Q2 [5]}}