Page 10 - Q & A STPM 2022 Physics

Chapter
1 Physical Quantities and

Units

Penerbitan Pelangi Sdn Bhd. All Rights Reserved.

1.1 Base Quantities and SI Units

Section A Multiple-choice Questions Semester

Question 1 1
Which of the following is not true about the unit for each physical quantity?
A Momentum : kg m s –1
B Impulse : N s
C Energy : kg m s –2
–2
D Pressure : N m –2

Answer: C
A Momentum = mass × velocity
Exam Tips
Unit = kg m s –1 Exam Tips
B Impulse = force × time Base quantities and their SI
Unit = N s units:
C Energy (work) = force × displacement Mass (kg), length (m), time (s),
= mass × acceleration × displacement current (A), temperature (K),
2
–2
Unit = kg × m s × m = kg m s –2 quantity of matter (mol).
D Pressure = force ÷ area
2
Unit = N ÷ m = N m –2
Question 2

The gravitational force between two masses placed a distance r apart is
represented by the equation GMm . The unit for the gravitational constant G is
2
2
A N m kg –2 r
B N m kg 2
–1
C N m kg 2
–2
D N m kg –2
Answer: A 2
G = Fr
Mm
2
Unit G = N m 2 = N m kg –2
kg 2
1

01 STPM Q&A PHY T1.indd 1 17/02/2022 10:03 AM