AQA GCSE Physics 21 Motion

1
AQA GCSE Physics 2-1Motion

• GCSE Physics pages 120 to 131

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AQA GCSE Specification

• DESCRIBING MOVEMENT
• 12.1 How can we describe the way things move?
• Using skills, knowledge and understanding of how
  science works
• to construct distance-time graphs for a body
  moving in a straight line when the body is
  stationary or moving with a constant speed
• to construct velocity-time graphs for a body
  moving with a constant velocity or a constant
  acceleration
• HT to calculate the speed of a body from the
  slope of a distance-time graph
• HT to calculate the acceleration of a body from
  the slope of a velocity-time graph
• HT to calculate the distance travelled by a body
  from a velocity-time graph.
• Skills, knowledge and understanding of how
  science works set in the context of
• The slope of a distance-time graph represents
  speed.
• The velocity of a body is its speed in a given
  direction.
• The acceleration of a body is given by
• acceleration change in velocity / time taken
  for change
• The slope of a velocity-time graph represents
  acceleration.
• The area under a velocity-time graph
  represents distance travelled.

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Distance-time graphsNotes questions from pages
120 121

• Copy the equation for speed, along with the units
  used, at the bottom of page 120.
• Copy Figure 2 on page 120 and explain how a
  distance-time graph can be used to find speed.
• Copy and answer question (a) on page 120.
• Copy Figure 3 on page 121 and then copy and
  answer questions (b), (c) and (d) on page 121.
• Copy the Key Points on page 121.
• Answer the summary questions on page 121.

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Distance-time graphs ANSWERS

• In text questions
• It would not have been as steep.
• 25 m/s
• 600 s
• 11.1 m/s

• Summary questions
• (a) Speed
• (b) Speed, distance. (c) Speed.
• (a) 30 m/s
• (b) 9000 m

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Velocity and acceleration Notes questions from
pages 122 123

• Explain the difference between speed and
  velocity.
• Explain how it is possible to be moving with a
  constant speed while changing in velocity.
• Copy and answer question (a) on page 122.
• (a) What is acceleration? (b) Copy the equation
  for acceleration, along with the units used, on
  page 123.
• Repeat the worked example shown on page 123 but
  this time change the time taken to 9 seconds.
• Copy and answer question (b) on page 123.
• Explain the meaning of deceleration.
• Copy the Key Points on page 123.
• Answer the summary questions on page 123.

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Velocity and acceleration ANSWERS

• In text question
• 600 m
• 2.5 m/s2

• Summary questions
• (a) Speed.
• (b) Acceleration.
• (c) Velocity.
• (a) 20 m/s
• (b) 2.5 m/s2

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More about velocity-time graphs Notes questions
from pages 124 125and also page 123

• Copy Figure 4 from page 123 graph X ONLY.
• Explain how acceleration can be found from a
  velocity-time graph and hence find the
  acceleration represented by graph X.
• Copy Figure 3 from page 125 and describe the
  motion shown by this graph. You should include a
  calculation of the deceleration caused by
  braking.
• Copy and answer question (b) on page 125.
• How can distance travelled be found from a
  velocity-time graph?
• Copy and answer question (c) on page 125.
• Copy the Key Points on page 125.
• Answer the summary questions on page 125.

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More about velocity-time graphs ANSWERS

• In text questions
• Less steep
• It would not be as steep
• Greater

• Summary questions
• 1. 1.B 2.A 3.D 4.C
• 2. (a) A (b) C

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Using graphs Notes questions from pages 126 127

• Copy and answer questions (a) and (b) on page
  126.
• Copy Figure 3 on page 126 and copy the
  calculations of the acceleration and the distance
  travelled over the ten second period shown on
  page 127.
• Copy the Key Points on page 127.
• Answer the summary questions on page 127.
• NOTE Graph paper needed for Q2.

10
Using graphs ANSWERS

• In text questions
• 15 m/s
• The speed decreased gradually and became
  constant.

• Summary questions
• (a) The cyclist accelerates with a constant
  acceleration for 40s, and then decelerates to a
  standstill in 20s.
• (b) (i) 0.2 m/s2
• (ii) 160 m
• 2. (a) Graph
• (b) 2 m/s2
• (c) (i) 400m
• (ii) 400 m

11
Transport issues Notes questions from pages 128
129

• Answer questions 1 and 2 on page 128.

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Transport issues ANSWERS

• (a) (i) 5 litres (ii) 4 litres
• (b) 1.70
• Journey 1 6.7 km/h
• Journey 2 4000 km/h

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How Science Works ANSWERS

• They were base on non-scientific evidence. It
  could be hearsay or even prejudice. It is
  unlikely that ALL cars exceeded the speed limit.
• Difficult to prove a casual relationship here.
  Evidence would be needed from both before and
  after the installation of road bumps at both
  sites.
• Time for cars to cover a suitable distance
  recorded. Speed distance / time.

• Survey should be carried out at sample times at
  regular intervals during the day, for example 10
  minutes every hour. A fair test with valid
  results.
• As many as possible, but at least 10 in each
  sample. A preliminary test could be used to
  determine the best number and how often.
• No. Otherwise drivers might behave differently.
  This is part of the control in such surveys.