Banner 1
7.1 Speed and velocity AQA AS Physics C7 On The Move Kerboodle Answers: Page No. 119
1.Ans-
a km/h
80kmh-1
b ms-1.
22ms-1
2.Ans-a
2.5 m s-1
b
3.0 ms-1
3.Ans-a
2.5 X 104 kmh-1
b 7.0 x 103 ms-1
4.Ans-
a
45000m
b
5.Ans- a
b i
4.0 km
ii 30ms-1 then 25ms-1 in the opposite direction
7.2 Acceleration AQA AS Physics C7 On The Move Kerboodle Answers: Page No. 121
1. a1.5ms-2
b A-2.5 ms-2
2.a0.45 ms-2
b .
7.9 ms-1
3 a Sketch a velocity—time graph to represent its journey.
b 0.60ms-2, 0, -0.40ms-2
4
Describe how
a the velocity of the object changed with time,
b the acceleration of the object changed with time.
7.3 Motion along a straight line at constant acceleration AQA AS Physics C7 On The Move Kerboodle Answers : Page No. 124
1.a 2.0 ms-2
b 221m
2.a 43s
b -0.93ms-2
3.a
i the acceleration,
0.2 m s-2
ii the displacement.
90 m
b
i -0.75ms-2
ii 8.0 s
d 3.0ms-1
4. a5.0ms-2
b the displacement in the first s
7.5m
c the displacement in the next 2 S
18m
d the average speed over the first 4 s.
6.4ms-1
7.4 Free fall AQA AS Physics C7 On The Move Kerboodle Answers : Page No. 127
1.4.0m
b its speed just before hitting the water.
8.8ms-1
2.
a the time taken for the spanner to hit the ground
3.2s
b the speed of impact of the spanner on hitting the ground.
31 ms-1
3.3.9s
ii the speed of impact of the object on hitting the water, assuming air resistance is negligible.
38ms-1
4.a the acceleration due to gravity On the Moon
1.6ms-2
b the speed of projection of the object
3.6ms-1
c 0.64m
7.5 Motion graphs AQA AS Physics C7 On The Move Kerboodle Answers : Page No. 129
1.a Calculate how long the swimmer takes to swim from
i the starting end to the other end,
83 s
ii back to the start from the other end.
127 s
b For the swim from starltc finish, sketch
i a displacement—time graph,
ii a distance—time graph,
iii a velocity—time graph.
2.a Calculate how long the motorcyclist has to wait before the cyclist catches up.
600 s
b Cn the same axes, sketch velocity—time graphs for
i the motorcyclist,
ii the cyclist.
3.
a Sketch a graph to show how the velocity of the object changed with time during its descent.
Velocity/ m s-1
b Show that the balloon base wag 33.6 above the ground when the object fell off the base.
4.a Given 9 ms-a, calculate
i the duration Of its descent,
0.61 s
ii its velocity just before impact,
5.9 ms-1
iii the duration of its ascent,
0.43 s
iv its velocity just after impact.
4.2 ms-1.
7.6 More calculations on motion along a straight line AQA AS Physics C7 On The Move Kerboodle Answers : Page No. 131
1.a Calculate
i the time taken to reach 29 ms-1 from 4 m s- l,
52s
ii its acceleration during this time.
0.49ms-2
b Calculate
i the distance it travelled during deceleration,
406m
ii its deceleration for the last 28s.
-1.04ms-2
2.a the distance it moved up the incline
15 m
b its acceleration on the incline
-0.13ms-2
c its velocity and position on the incline after
0.67ms-1 downwards, 13.4m from the start
3.a Calculate i the distance travel led by the cyclist in the first 20 s,
80m
ii the speed of the cyclist at the end Of this time.
8.0ms-1
b Calculate
i the time taken to cover the distance of 260m after she stopped pedalling,
65s
ii her deceleration during this time.
-0.12ms-2
4.a Calculate
i its velocity,
180ms-1
ii its height above the launch pad when its motors switched off.
2.7 km
b Calculate the maximum height reached after its motors switched off,
4.4km
c Calculate the velocity with which it would hit the ground if it fell from maximum height without the support of a parachute.
290ms-1
Banner 7
7.7 Projectile motion 1 AQA AS Physics C7 On The Move Kerboodle Answers : Page No. 133
1 a the velocity of the object at the ground
32ms-1
b the duration of descent
2.8s
c the height of the balloon above the ground when the object hits the ground.
39m
2.a how long it takes to reach the sea
3.0s
b how far it travels horizontally
49m
c its impact velocity.
34ms-1 (at 62° to the horizontal)
3.a the time of flight of the dart
0.20s
b its horizontal speed Of projection.
11.7ms-1
4.
a the height Of the aircraft above the ground
354m
b the horizontal distance travelled in this time bg
i the parcel,
1020m
ii the aircraft
1020m
c the speed of impact of the parcel at the ground.
146ms-1
7.8 Projectile motion 2 AQA AS Physics C7 On The Move Kerboodle Answers : Page No. 135
1.
a 470mm
b 3.0ms-2
c 2.7ms-1
2 a 2.02s
b50.5m
3
a3.5ms-1, 3.0ms-1
b150m
ii 20m
Banner 8
Practice questions: Page No. 136-137
1.(a) )
(b)
2 .
(a) AB: uniform acceleration
BC: constant velocity
CD: uniform deceleration
DE: stationary
EF: uniform acceleration in the opposite direction
(b) Displacement is equal to the area enclosed by the graphs and the time axis
(c) Distance is a scalar and is represented by the total area under both the positive and negative portions of the graph whereas displacement is a vector and the areas abo’ve and below the v = 0 line are equal and therefore cancel
3.(a)
Using v = u + a t gives 12 = 4 + 6.0 a
∴acceleration a = 1.3 m s-2
(b)
(c) Distance travelled = area under graph
= area of trapezium with vertical sides of 4 m s-1 and 12 m s-1 = 1/2 × (4 + 12) × 6.0
= 48 m
4 .(a) (i) Using v = u + a t gives 0 = 4.5 + 3600 a
∴ Acceleration a = −1.3 × 10-3 m s-2 and deceleration = 1.3 × 10-3 m s-2
(ii)
(b) (c) • Gradient of graph = speed
• Speed decreases giving a decreasing gradient
• Gradient is zero when stationary
5.(a)
i) Its acceleration
Using v = u + a t gives 29 = 0 + 2.0 a
∴ Acceleration a = 14.5 m s-2
(ii)
(iii)
Using distance = (speed) × (time) gives
s = 29 × 15 = 435 m
(b)
(i) Using the same axes plot the speed—time graph for the antelope during the chase.
(ii)
(iii)
6 (a)
(b) A lower value would be obtained for g
Because air resistance has a greater effect on the tennis ball
Resulting in a smaller resultant downwards force on the tennis ball
(c)
7 (a) Horizontal velocity remains 70 m s-1
(b) Using v = u + a t gives vertical velocity
vV = 0 + (9.81 × 2.0)
= 19.6 m s-1
(c)
Banner 9
DISCLAIMER
Disclaimer: I have tried by level best to provide the answers and video explanations to the best of my knowledge. All the answers and notes are written by me and if there is any similarity in the content then it is purely coincidental. But this is not an alternative to the textbook. You should cover the specification or the textbook thoroughly. This is the quick revision to help you cover the gist of everything. In case you spot any errors then do let us know and we will rectify it.
References:
BBC Bitesize
AQA GCSE Science Kerboodle textbook
Wikipedia
Wikimedia Commons
Join Our Free Facebook Group : Get A* in GCSE and A LEVEL Science and Maths by Mahima Laroyia: https://www.facebook.com/groups/expertguidance.co.uk/
For Free Tips, advice and Maths and Science Help
