Physics (5058 /01)
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Ans
1
version 1.1
Workings/Remarks
C
End correction = 0.2cm
Actual length of object X = 1.1 + 0.2 = 1.3cm
2
D
Force, Acceleration, Velocity and Displacement are vectors. Work, Time and Mass are scalars. 3
D
Gradient of speed-time graph = acceleration
Changing gradient (curve) = non uniform acceleration
Constant gradient (straight line) = uniform acceleration
4
C
… 9 dots …
20 cm
… 9 dots …
… 9 dots …
… 9 dots …
… 9 dots …
Noting that dots are shared across consecutive interval, we calculate based on the spacings between consecutive dots.
In each 20 cm interval, there are 11 dots ⇒ 10 spacings
⇒ Between 50 dots, there’s a total of 49 spacings.
× 10s
Since 50 dots/49 spacings are moved in 1 sec, time taken for 1 spacing =
Time taken to move 20 cm/10 spacings =
∴Speed of tape =
distance time =
20
1
×10
49
1
49
= 98 cm/s ≈ 100 cm/s
5
B
Resultant force = 10 – 2 = 8 N
6
C
A
Density is inversely proportional to volume (Density = Mass / Volume)
8
A
s
Acceleration = (30 – 10) / 16 = 1.25 m/s2
7
1
49
Clockwise moment = 1.5 × (50 − 30) = 30 N cm
The weight of 5N (towards centre of earth/downwards on trolley) is not included in the calculation because it is not acting in the same direction as the motion of trolley (along a level bench).
F = ma = 12000 × 1.25 = 15000N
Minimum volume = Maximum density and vice versa
Anticlockwise moment = 2 × (30 −15) = 30 N cm
Resultant moment is the difference between clockwise and anticlockwise moment.
9
B
Pressure = Force / Area = Weight / Area
A: P = 30/100
= 0.3 N/cm2
B: P = 500/150
= 3.33 N/cm2
C: P = 750 / 300
= 2.5 N/cm2
D: P = 10000 / 4000 = 2.5 N/cm2
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