CAIE M1 2016 November — Question 1 5 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2016
SessionNovember
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicWork done and energy
TypeLifting objects vertically
DifficultyEasy -1.2 This is a straightforward application of basic work-energy formulas (W = Fd, P = W/t) with constant forces and vertical motion. Requires only direct substitution into standard formulas after identifying that the crane must overcome both weight (mg) and resistance, making it easier than average A-level questions which typically involve multi-step problem-solving or conceptual challenges.
Spec6.02a Work done: concept and definition6.02b Calculate work: constant force, resolved component6.02l Power and velocity: P = Fv

1 A crane is used to raise a block of mass 50 kg vertically upwards at constant speed through a height of 3.5 m . There is a constant resistance to motion of 25 N .
  1. Find the work done by the crane.
  2. Given that the time taken to raise the block is 2 s , find the power of the crane.

Question 1:
Part (i)
AnswerMarks Guidance
Answer/WorkingMark Guidance
PE gain \(= 50g \times 3.5 \ (=1750)\)B1
\([WD = 50g \times 3.5 + 25 \times 3.5]\)M1 For using \(WD = \text{PE gain} + WD\) against resistance
Work done \(= 1837.5\text{ J}\) or \(1840\text{ J}\)A1 [3]
Part (ii)
AnswerMarks Guidance
Answer/WorkingMark Guidance
\([P = 1837.5/2]\) or \([P/v = 50g + 25\) and \(3.5 = 2v]\)M1 For using \(P = WD/t\) or for using \(P = Fv\) and \(s = vt\)
Power \(= 919\text{ W}\)A1 [2]
# Question 1:

## Part (i)
| Answer/Working | Mark | Guidance |
|---|---|---|
| PE gain $= 50g \times 3.5 \ (=1750)$ | B1 | |
| $[WD = 50g \times 3.5 + 25 \times 3.5]$ | M1 | For using $WD = \text{PE gain} + WD$ against resistance |
| Work done $= 1837.5\text{ J}$ or $1840\text{ J}$ | A1 | [3] |

## Part (ii)
| Answer/Working | Mark | Guidance |
|---|---|---|
| $[P = 1837.5/2]$ or $[P/v = 50g + 25$ **and** $3.5 = 2v]$ | M1 | For using $P = WD/t$ or for using $P = Fv$ and $s = vt$ |
| Power $= 919\text{ W}$ | A1 | [2] |

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1 A crane is used to raise a block of mass 50 kg vertically upwards at constant speed through a height of 3.5 m . There is a constant resistance to motion of 25 N .\\
(i) Find the work done by the crane.\\
(ii) Given that the time taken to raise the block is 2 s , find the power of the crane.

\hfill \mbox{\textit{CAIE M1 2016 Q1 [5]}}