Online Test — Motion
20 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 20
Which of the following is a scalar quantity?
Velocity
Displacement
Distance
Acceleration
Explanation: Distance has magnitude only, so it is a scalar.
Question 2 of 20
Displacement of an object that returns to its starting point is:
Equal to distance
Maximum
Zero
Negative
Explanation: Start and end coincide, so the shortest gap (displacement) is zero.
Question 3 of 20
The SI unit of speed is:
m/s
km/h
m/s$^2$
m
Explanation: Speed = distance/time, so its SI unit is m/s.
Question 4 of 20
54 km/h in m/s is:
10 m/s
15 m/s
20 m/s
5 m/s
Explanation: 54 x 5/18 = 15 m/s.
Question 5 of 20
Acceleration is the rate of change of:
Distance
Velocity
Displacement
Speed only
Explanation: Acceleration = (v - u)/t, the rate of change of velocity.
Question 6 of 20
A car slows from 25 m/s to 5 m/s in 4 s. Its acceleration is:
+5 m/s$^2$
-5 m/s$^2$
-20 m/s$^2$
+20 m/s$^2$
Explanation: a = (5 - 25)/4 = -5 m/s$^2$ (retardation).
Question 7 of 20
Equal distances in equal time intervals indicate:
Non-uniform motion
Rest
Uniform motion
Accelerated motion
Explanation: This is the definition of uniform motion.
Question 8 of 20
The first equation of motion is:
$s = ut + \tfrac{1}{2}at^2$
$v = u + at$
$v^2 = u^2 + 2as$
$s = vt$
Explanation: v = u + at relates final velocity, initial velocity, acceleration and time.
Question 9 of 20
A body starts from rest with a = 3 m/s$^2$. Distance in 4 s is:
12 m
24 m
48 m
6 m
Explanation: s = 0 + (1/2)(3)(16) = 24 m.
Question 10 of 20
The slope of a distance-time graph gives:
Acceleration
Speed
Displacement
Time
Explanation: Slope = distance/time = speed.
Question 11 of 20
The area under a velocity-time graph gives:
Speed
Acceleration
Displacement
Force
Explanation: Area = velocity x time = displacement.
Question 12 of 20
A horizontal line on a distance-time graph means the object is:
Speeding up
At rest
Slowing down
Accelerating
Explanation: No change in distance with time means the object is at rest.
Question 13 of 20
Which quantity can be negative, positive or zero?
Distance
Speed
Displacement
Time
Explanation: Displacement is a vector and can be positive, negative or zero.
Question 14 of 20
A train at 20 m/s stops in 100 m. Its retardation is:
1 m/s$^2$
2 m/s$^2$
4 m/s$^2$
5 m/s$^2$
Explanation: 0 = 20^2 + 2a(100) => a = -2 m/s$^2$; retardation = 2 m/s$^2$.
Question 15 of 20
Average speed is defined as:
Displacement/time
v - u over t
u + v
Total distance/total time
Explanation: Average speed = total distance / total time.
Question 16 of 20
A v-t graph that is a flat horizontal line (above the axis) shows:
Uniform acceleration
Retardation
Constant velocity
Object speeding up
Explanation: Constant velocity means zero acceleration, so the v-t line is flat.
Question 17 of 20
If u = 0, the second equation of motion becomes:
$s = vt$
$s = \tfrac{1}{2}at^2$
$s = at$
$s = ut$
Explanation: With u = 0, s = ut + (1/2)at^2 reduces to s = (1/2)at^2.
Question 18 of 20
A body moving at 6 m/s accelerates to 10 m/s over 8 m. The acceleration is:
2 m/s$^2$
4 m/s$^2$
1 m/s$^2$
8 m/s$^2$
Explanation: 10^2 = 6^2 + 2a(8) => 100 = 36 + 16a => 16a = 64 => a = 4 m/s$^2$.
Question 19 of 20
Which of these has the same SI unit as velocity?
Acceleration
Speed
Distance
Time
Explanation: Both speed and velocity have the SI unit m/s.
Question 20 of 20
1 m/s is equal to how many km/h?
3.6 km/h
5 km/h
18 km/h
0.6 km/h
Explanation: 1 m/s x 18/5 = 3.6 km/h.