1. What is the SI unit of the centre of mass position of a uniform rod?
A.
metre
B.
kilogram
C.
second
D.
newton
Correct Answer:
metre
Explanation:
The position of the centre of mass is a length, so its SI unit is the metre (m).
2. The dimensional formula of the distance of the centre of mass from one end of a uniform rod is:
A.
[L]
B.
[M]
C.
[T]
D.
[MLT⁻²]
Correct Answer:
[L]
Explanation:
The distance of the centre of mass is a length, whose dimensional formula is [L].
3. A uniform rod has its centre of mass at a distance of 0.5 m from one end. What is this distance in centimetres?
A.
5 cm
B.
50 cm
C.
500 cm
D.
0.05 cm
Correct Answer:
50 cm
Explanation:
Since 1 m equals 100 cm, 0.5 m equals 50 cm.
4. Which unit is most suitable for expressing the centre of mass position of a laboratory-sized uniform rod?
A.
metre
B.
kilogram
C.
ampere
D.
kelvin
Correct Answer:
metre
Explanation:
The centre of mass position is measured as a distance, so metre is the suitable SI unit.
5. The centre of mass of a uniform rod of length 2 m is at its midpoint. What is its distance from either end?
A.
0.5 m
B.
1 m
C.
2 m
D.
4 m
Correct Answer:
1 m
Explanation:
For a uniform rod, the centre of mass is at the midpoint. Half of 2 m is 1 m.
6. Which of the following is a valid unit for the coordinate of the centre of mass of a uniform rod?
A.
cm
B.
kg
C.
N
D.
J
Correct Answer:
cm
Explanation:
A centre of mass coordinate represents length, so centimetre is a valid unit.
7. A uniform rod is 80 cm long. In which unit can the position of its centre of mass from an end be written?
A.
40 cm
B.
40 kg
C.
40 s
D.
40 N
Correct Answer:
40 cm
Explanation:
The centre of mass is at the midpoint, 40 cm from either end. The position must have a length unit.
8. If the length of a uniform rod is measured in millimetres, the position of its centre of mass should also be expressed in:
A.
millimetres
B.
kilograms
C.
seconds
D.
newtons
Correct Answer:
millimetres
Explanation:
The centre of mass position and the rod length are both lengths, so their units can consistently be millimetres.
9. The centre of mass of a uniform rod of length 1.2 m is located at:
A.
0.6 m from either end
B.
1.2 kg from either end
C.
0.6 s from either end
D.
1.2 N from either end
Correct Answer:
0.6 m from either end
Explanation:
The centre of mass of a uniform rod lies at its midpoint, and half of 1.2 m is 0.6 m.
10. Which physical quantity has the same unit as the position of the centre of mass of a uniform rod?
A.
length of the rod
B.
mass of the rod
C.
time taken by the rod
D.
force acting on the rod
Correct Answer:
length of the rod
Explanation:
The position of the centre of mass is a length, so it has the same unit as the length of the rod.
Short questions are currently unavailable for this page.