10 physics answers
Edexcel IGCSE physics Chapter 1
1. 100m/12.5s = 8m/s
2. a) 350m/s x 30s = 10500m (10.5km)
b) 350m/s x 60s x 5 = 105000m (105km)
c) 350m/s x 60s x 30 = 630000m (630km)
3. t = d/v, so 1.6m/0.0004m/s = 4000s (67 minutes)
4. a) D
b) C
c) A
d) B
5.
6.
0.35
0.3
0.25
Time (s)
0.2
0.15
0.1
0.05
0
0.00
2.00
4.00
6.00
Distance (m)
8.00
10.00
12.00
7. a) The car is moving at constant velocity (the intervals between drips are regular, and direction is not
changing)
b) 6 time intervals = 6 x 2.5 = 15s
v = d/t = 135m/15s = 9m/s
10 physics answers
Edexcel IGCSE physics Chapter 1
8. a)
16
14
12
10
Velocity (m/s) 8
6
4
2
0
0
1
2
3
Time (s)
4
5
6
b) From the graph (coloured area), average velocity = v + u = 35 + 20 = 22.5 m/s
2
2
d = average velocity x time = 22.5m/s x 5s = 112.5m
9. a) average speed is the speed over the entire period of the journey, and is calculated as:
total distance/total time taken
Instantaneous speed is the speed at a particular moment in time. On a Speed-Time graph, the
instantaneous speed can be taken from any point which lies on the line (e.g in the graph above, at time
= 4 seconds, instantaneous speed = 32m/s)
b) speed is a scalar quantity, i.e. it has magnitude (size) but no particular direction. Velocity is a vector
quantity, i.e. it has magnitude and direction.
10. a = Δv/Δt = 24m/s / 6s = 4m/s2
10 physics answers
Edexcel IGCSE physics Chapter 1
11. a)
16
14
12
10
Velocity (m/s)
8
6
4
2
0
0
1
2
3
4
5
6
b)
35
30
25
20
Velocity (m/s)
15
10
5
0
0
2
4
6
8
10
12
c)
16
14
12
10
Velocity (m/s)
8
6
4
2
0
0
1
2
3
4
5
6
10 physics answers
Edexcel IGCSE physics Chapter 1
12. The speed/time graph of the journey is shown:
80
70
60
Velocity (m/s)
50
40
30
20
10
0
0
5
10
15
20
a) after 1s the velocity has increased by 3m/s
b) after 5s it has increased by 15m/s from rest (see arrows)
c) after 25s it has increased by 25m/s from rest
13. a) B
b) A
c) D
d) C
speed
14.
5s
15s
17s
time
25
30
10 physics answers
Edexcel IGCSE physics Chapter 1
15.
12
Velocity (m/s)
10
8
6
4
2
0
0
2
4
6
8
10
Time (s)
a) a = Δv/Δt = 10m/s / 4s = 2.5m/s2
b) (i) d = ½(10m/s x 4s) = 20m (area of blue triangle)
(ii) d = 10m/s x 5s = 50m (area of red rectangle)
c) Average speed = total distance (from b), 20m + 50m = 70m) = 70m / 9s = 7.8m/s
total time
10 physics answers
Edexcel IGCSE physics Chapter 1
16. Use a ruler to measure the distance between drips and record as follows:
Time (s)
Distance
between drips
in picture
(mm)
0
1
2
3
4
5
If 4mm in drawing = 0.5m,
Distance
between drips
(m)
4
9
14.5
20
28
Speed (m/s)
0.50
1.13
1.81
2.50
3.50
5.0
11.3
18.1
25.0
35.0
the conversion factor = (500mm/4mm) divided by 1000mm in a metre = 0.125
Speed (m/s)
Speed/time graph:
40
35
30
25
20
15
10
5
0
0
1
2
3
Time (s)
Use Δv = 35m/s, and Δt = 5s, so a = 7m/s
2
4
5
6