Less than or equal to it. |\bar{\vec v}| = \frac{|\text{displacement}|}{t} \leq \frac{\text{distance}}{t} = average speed.

Question 1

Velocity is a

Accepted Answer

Vector quantity. Velocity is speed WITH direction — a vector.

Question 2

Average velocity is defined as

Accepted Answer

Displacement ÷ time. \bar{\vec v} = \frac{\Delta\vec r}{\Delta t} — it uses displacement, not path length.

Question 3

A jogger returns to her starting point after a 30-minute run. Her average velocity is

Accepted Answer

Zero. Round trip \Rightarrow zero displacement \Rightarrow zero average velocity (average speed is non-zero).

Question 4

Instantaneous velocity is given by

Accepted Answer

\frac{dx}{dt}. Velocity is the time derivative of position.

Question 5

The position of a particle is x = 3t^2 (metres, seconds). Its velocity at t = 2 s is

Accepted Answer

12 m/s. v = \frac{dx}{dt} = 6t; at t = 2: v = 12 m/s.

Question 6

A body moving with uniform velocity has

Accepted Answer

Zero acceleration. Uniform velocity means neither the magnitude nor direction changes — so a = 0.

Question 7

In one-dimensional motion, velocity

Accepted Answer

Can be positive, negative or zero. The sign encodes direction along the axis.

Question 8

The position of a particle is x = 5 + 4t (metres, seconds). Its velocity is

Accepted Answer

4 m/s. v = \frac{dx}{dt} = 4 m/s — uniform velocity (the 5 m is just the starting position).

Question 9

The magnitude of average velocity compared with average speed is

Accepted Answer

Less than or equal to it. |\bar{\vec v}| = \frac{|	ext{displacement}|}{t} \leq \frac{	ext{distance}}{t} =  average speed.

Question 10

Can the velocity of a body change while its speed remains constant?

Accepted Answer

Yes — if the direction changes (e.g. circular motion). Velocity is a vector: changing direction alone changes velocity.

Question 11

Two trains run at 60 km/h and 40 km/h in OPPOSITE directions. The magnitude of their relative velocity is

Accepted Answer

100 km/h. Opposite directions: relative speed = 60 + 40 = 100 km/h.

Question 12

Two cars travel in the same direction at 80 km/h and 50 km/h. The velocity of the faster car relative to the slower one is

Accepted Answer

30 km/h forward. \vec v_{rel} = 80 - 50 = 30 km/h in the direction of motion.

Question 13

A particle moves as x = t^3 - 3t^2 (metres, seconds). Its velocity is zero at the non-zero time t =

Accepted Answer

2 s. v = 3t^2 - 6t = 3t(t-2) = 0 \Rightarrow t = 0 or t = 2 s.

Question 14

A particle at rest necessarily has

Accepted Answer

Zero velocity. Rest means velocity zero; its position can be anywhere, and acceleration may even be non-zero momentarily.

Question 15

A body moves at 5 m/s for 10 s, then stays at rest for 10 s (no reversal). Its average velocity over the 20 s is

Accepted Answer

2.5 m/s. Displacement = 50 m in 20 s: \bar v = 2.5 m/s.

Question 16

A negative velocity in one-dimensional motion means the particle is

Accepted Answer

Moving in the negative direction of the axis. The sign of v gives direction only — it says nothing about speeding up or slowing down.

Question 17

A car moving east at 40 km/h turns around and moves west at 40 km/h. The magnitude of its change in velocity is

Accepted Answer

80 km/h. \Delta v = (-40) - (+40) = -80: magnitude 80 km/h, directed west.

Question 18

The slope of the tangent to a position–time graph at an instant gives

Accepted Answer

Instantaneous velocity. v = \frac{dx}{dt} — geometrically the slope of the tangent at that point.

Question 19

A man walks 100 m east in 50 s, then 100 m west in 50 s. His average velocity for the whole trip is

Accepted Answer

Zero. Net displacement is zero, so average velocity = 0 (average speed is 2 m/s).

Question 20

A body has uniform velocity if it covers

Accepted Answer

Equal displacements in equal intervals of time. Uniform velocity: same displacement (magnitude AND direction) every equal time interval.

Velocity — JEE Main Physics MCQs with Solutions

Questions with solutions