CAIE M1 2016 November — Question 3 6 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2016
SessionNovember
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSUVAT in 2D & Gravity
TypeVertical projection: max height
DifficultyModerate -0.8 This is a straightforward two-part SUVAT question requiring direct application of standard kinematic equations with constant acceleration. Part (i) uses v² = u² + 2as to find maximum height, and part (ii) uses s = ut + ½at² to find return time. Both are routine textbook exercises with no problem-solving insight required, making it easier than average.
Spec3.02h Motion under gravity: vector form

3 A particle \(P\) is projected vertically upwards from a point \(O\). When the particle is at a height of 0.5 m , its speed is \(6 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). Find
  1. the greatest height reached by the particle above \(O\),
  2. the time after projection at which the particle returns to \(O\).

Question 3(i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\([0 = 6^2 - 2g \times s]\)M1 For using \(v^2 = u^2 + 2as\)
\(s = 1.8\)A1
Total height \(= 2.3\text{ m}\)B1 [3]
Alternative for 3(i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\([6^2 = u^2 - 2g \times 0.5]\)M1 For using \(v^2 = u^2 + 2as\) to find the initial velocity
\(u^2 = 46\)A1
\(0^2 = 46 - 2gs \rightarrow s =\) total height \(= 2.3\text{ m}\)B1 [3]
Question 3(ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\([2.3 = 0 + 0.5gt^2]\)M1 For using \(s = ut + 0.5gt^2\) to find time to reach the ground
\(t = 0.678\)A1
Total time \(= 2 \times 0.678 = 1.36\text{ s}\)B1 [3]
Alternative for 3(ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\([0 = \sqrt{46} - gt]\)M1 Using \(v = u - gt\) to find time taken to the highest point
\(t = \dfrac{\sqrt{46}}{10} = 0.678\)A1
Total time \(= 2 \times 0.678 = 1.36\text{ s}\)B1 [3]
## Question 3(i):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $[0 = 6^2 - 2g \times s]$ | M1 | For using $v^2 = u^2 + 2as$ |
| $s = 1.8$ | A1 | |
| Total height $= 2.3\text{ m}$ | B1 | [3] |

**Alternative for 3(i):**

| Answer/Working | Mark | Guidance |
|---|---|---|
| $[6^2 = u^2 - 2g \times 0.5]$ | M1 | For using $v^2 = u^2 + 2as$ to find the initial velocity |
| $u^2 = 46$ | A1 | |
| $0^2 = 46 - 2gs \rightarrow s =$ total height $= 2.3\text{ m}$ | B1 | [3] |

## Question 3(ii):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $[2.3 = 0 + 0.5gt^2]$ | M1 | For using $s = ut + 0.5gt^2$ to find time to reach the ground |
| $t = 0.678$ | A1 | |
| Total time $= 2 \times 0.678 = 1.36\text{ s}$ | B1 | [3] |

**Alternative for 3(ii):**

| Answer/Working | Mark | Guidance |
|---|---|---|
| $[0 = \sqrt{46} - gt]$ | M1 | Using $v = u - gt$ to find time taken to the highest point |
| $t = \dfrac{\sqrt{46}}{10} = 0.678$ | A1 | |
| Total time $= 2 \times 0.678 = 1.36\text{ s}$ | B1 | [3] |

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3 A particle $P$ is projected vertically upwards from a point $O$. When the particle is at a height of 0.5 m , its speed is $6 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. Find\\
(i) the greatest height reached by the particle above $O$,\\
(ii) the time after projection at which the particle returns to $O$.

\hfill \mbox{\textit{CAIE M1 2016 Q3 [6]}}