Essays
Answers
Chapter 1
1
a)
8 m/s
2
a)
10 500 m (10.5 km)
b) 105 000 m (105 km)
c)
630 000 m (630 km)
4000 s (Snails can actually move faster than this! At a more realistic 4 mm/s (0.004 m/s) it would only take the snail 400 s or 6 minutes 40 seconds.)
4
a)
graph D
b) graph C
c)
graph A
d) graph B
a)
8m distance =
= 32 m/s
0.25s
time
The car is moving at constant velocity (speed).
5
IGCSE Physics Answers – Section A
3
6
gradient =
7
b) Time interval between first and seventh drip is 15 s (6
135 m ÷ 15 s = 9 m/s.
8
2.5 s) so average speed is
a)
1
b) Distance travelled is given by the area under the graph
= (5 s
20 m) + (0.5
5s
15 s)
= 137.5 m
9
a)
Average speed is found by dividing the total distance a body has travelled by the time it has taken; the speed may vary from moment to moment during this time. The instantaneous speed is the speed at which the body is travelling at a moment in time.
IGCSE Physics Answers – Section A
b) Speed is a scalar quantity – it is distance travelled divided by time without regard to direction.
Velocity is a vector quantity – it is speed in a specified direction.
10 4 m/s2
11 a)
b)
c)
12 a)
3 m/s
b) 15 m/s
c)
13 a)
75 m/s graph B
b) graph A
c)
graph D
d) graph C
2
14
a)
2.5 m/s2
b ) i)
20 m
ii)
50 m
c)
average speed = total distance travelled ÷ time taken.
IGCSE Physics Answers – Section A
15
= 70 m ÷ 9 s
= 7.78 m/s
16 The total distance travelled increases with the square of the time from the start, 0.5 m after 1 s, 2.0 m after 2 s, 4.5 m after 3 s, etc. Calculating the average velocity over each 1 s time interval (between the drips) and then plotting a graph of average velocity against time allows the acceleration to be calculated from the gradient of the graph. The acceleration is 1 m/s2.
Chapter 2
1
a)
gravity
b) friction
Chapter 1
1
a)
8 m/s
2
a)
10 500 m (10.5 km)
b) 105 000 m (105 km)
c)
630 000 m (630 km)
4000 s (Snails can actually move faster than this! At a more realistic 4 mm/s (0.004 m/s) it would only take the snail 400 s or 6 minutes 40 seconds.)
4
a)
graph D
b) graph C
c)
graph A
d) graph B
a)
8m distance =
= 32 m/s
0.25s
time
The car is moving at constant velocity (speed).
5
IGCSE Physics Answers – Section A
3
6
gradient =
7
b) Time interval between first and seventh drip is 15 s (6
135 m ÷ 15 s = 9 m/s.
8
2.5 s) so average speed is
a)
1
b) Distance travelled is given by the area under the graph
= (5 s
20 m) + (0.5
5s
15 s)
= 137.5 m
9
a)
Average speed is found by dividing the total distance a body has travelled by the time it has taken; the speed may vary from moment to moment during this time. The instantaneous speed is the speed at which the body is travelling at a moment in time.
IGCSE Physics Answers – Section A
b) Speed is a scalar quantity – it is distance travelled divided by time without regard to direction.
Velocity is a vector quantity – it is speed in a specified direction.
10 4 m/s2
11 a)
b)
c)
12 a)
3 m/s
b) 15 m/s
c)
13 a)
75 m/s graph B
b) graph A
c)
graph D
d) graph C
2
14
a)
2.5 m/s2
b ) i)
20 m
ii)
50 m
c)
average speed = total distance travelled ÷ time taken.
IGCSE Physics Answers – Section A
15
= 70 m ÷ 9 s
= 7.78 m/s
16 The total distance travelled increases with the square of the time from the start, 0.5 m after 1 s, 2.0 m after 2 s, 4.5 m after 3 s, etc. Calculating the average velocity over each 1 s time interval (between the drips) and then plotting a graph of average velocity against time allows the acceleration to be calculated from the gradient of the graph. The acceleration is 1 m/s2.
Chapter 2
1
a)
gravity
b) friction