OCR M4 2007 June — Question 1 4 marks

Exam BoardOCR
ModuleM4 (Mechanics 4)
Year2007
SessionJune
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircular Motion 1
TypeAngular kinematics – constant angular acceleration/deceleration
DifficultyModerate -0.8 This is a straightforward application of constant angular acceleration equations (rotational analogues of SUVAT). Part (i) uses θ = ½αt² directly with given values, and part (ii) uses ω² = ω₀² + 2αθ. Both parts require only direct substitution into standard formulae with no problem-solving insight or multi-step reasoning required.
Spec6.05a Angular velocity: definitions

1 The driveshaft of an electric motor begins to rotate from rest and has constant angular acceleration. In the first 8 seconds it turns through 56 radians.
  1. Find the angular acceleration.
  2. Find the angle through which the driveshaft turns while its angular speed increases from \(20 \mathrm { rad } \mathrm { s } ^ { - 1 }\) to \(36 \mathrm { rad } \mathrm { s } ^ { - 1 }\).

1 The driveshaft of an electric motor begins to rotate from rest and has constant angular acceleration. In the first 8 seconds it turns through 56 radians.\\
(i) Find the angular acceleration.\\
(ii) Find the angle through which the driveshaft turns while its angular speed increases from $20 \mathrm { rad } \mathrm { s } ^ { - 1 }$ to $36 \mathrm { rad } \mathrm { s } ^ { - 1 }$.

\hfill \mbox{\textit{OCR M4 2007 Q1 [4]}}