Page 35 - Spotlight A+ Physics Form 4.5

Complete answers
ANSWERS http://bit.ly/3bHkxpp

24
FORM 4 (b) (i) Duration, T = ——
20
= 1.2 s
Chapter 1 Measurement Paper 1
10
1. D 2. A 3. A 4. A 5. D (ii) l = ————––— × (1.2) 2
1.1 6. B 7. A 8. C 9. B 10. C 4 × (3.142) 2
11. B 12. D 13. C 14. B 15. D = 0.36 m
1. (a) Length
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16. D 17. C 18. A 19. B 20. C
(b) Base unit: Meter; 21. A 22. B 23. A 24. B 25. D Section B
Symbol of unit: m 4. (a) Car Speed of car / m s –1
Magnitude: 1.55; Paper 2
Symbol of physical quantity: l Section A A 30.00
1. (a)
2. (a) Scalar quantity has magnitude Base quantity S.I. unit
only and vector quantity has both Length meter B 37.49
magnitude and direction. Time second C 25.20
(b) Scalar quantities: Distance, speed, Mass kilogram
time D 33.30
Length
Vector quantities: Acceleration (b) P = Force × ————
3. Base quantities: Time, mass, length kg m Time E 24.20
m
= ———— × —–
s
Derived quantities: Volume, area (c) S.I. unit is not same as metric (b) Both of them use walkie talkie
s × s
= kg m s
or smart phone. The time taken
2
–3
FORM 4 ANSWERS 1. (a) Graph functions as a visual tool unit because the time unit cannot (c) Malaysia speed limit
to pass through point O and P is
recorded and the time interval, t
1.2
is determined or other reasonable
be expressed in terms of 10.
method.
For example, 1 hour = 60 minutes
= 60 × 60 seconds
to represent the relationship

–1
= 110 km h
= 3 600 seconds.
between two physical quantities.
(b) Steps to analyse graph:
Thus, car B exceeds the speed
of tens or decimal-based but S.I.
(i) State the relationship Metric unit is based upon power = 30.56 m s –1
limit on Malaysia highway.
between two variables units of time cannot be expressed (d) Use the ultrasound detector,
(ii) Determine the gradient of in terms of 10. time tracker application or other
graph 2. (a) (i) Base quantity: Mass reasonable method. Record
(iii) Determine the area under (ii) Derived quantity: Force several readings on speed within
the graph (iii) Vector quantity: Force 5 km and calculate the average
(iv) Determine the value of (b) S.I. unit G values.
a physical quantity from Fr 2 5. (a) In old system: F = mlt –2
interpolation = ——— so, m = Ft l
Mm
2 –1
1
—
2
kg m × m
(v) Make a prediction through = ———————– In new FAω system: l = A ,
2

extrapolation s × s × kg × kg t = ω –1
–1
= kg m s –2 – 1 —
3
2 –1
2. (a) V increases so, m = Ft l = Fω A 2
–2
(b) V= 0 cm , θ = –250 °C 3. (a) (i) Time taken, T = 26 – 2 (b) There is no suitable measuring
3
θ = 300 °C, V =22 cm 3 = 24 s device to measure force, area and
(ii) To get the value of one frequency accurately.
V / cm 3 complete oscillation – There is no standard tool and
accurately. standard objects to determine
30 (iii) Repeat the experiment to get force, area and frequency.
22 cm 3 the average value of two sets – The unit for derived quantity
20
of readings for 20 complete becomes very complex and
10 oscillations. Use electronic or hinders the communications
–250°C
digital stopwatch to measure between physicist.
θ / °C
–300 –200 –100 0 100 200 300 the time more accurately. – or other reasonable answers.
520