Motion Basics: 19 MCQs with answers

Speed

Speed has only magnitude and no direction, making it a scalar. Velocity, displacement, and acceleration are vectors because they have both magnitude and direction.

Velocity

In a position-time graph, the slope (Δx/Δt) represents the rate of change of position, which is the velocity of the object.

60 km/h

Average speed = total distance / total time = 120 km / 2 h = 60 km/h.

Zero

Displacement is the change in position. Since the object returns to its starting point, the net change in position is zero, regardless of the distance traveled.

Zero

Acceleration is the rate of change of velocity. If velocity is constant, there is no change, so acceleration is zero.

Distance

Distance is a scalar quantity as it has only magnitude. Velocity, acceleration, and displacement are vectors.

Zero acceleration

Uniform velocity means no change in velocity, so acceleration is zero.

m/s²

Acceleration is the rate of change of velocity, so its unit is meters per second squared (m/s²).

Uniform speed

Equal distances in equal time intervals means constant speed. However, uniform velocity also requires constant direction, which is not guaranteed here.

False

Displacement is the shortest path between initial and final positions, so it is always less than or equal to the distance traveled.

Displacement

The area under a velocity-time graph gives the displacement of the object over the time interval.

Zero

At the highest point, the ball momentarily stops before falling back down, so its velocity is zero. However, its acceleration is still g (downward).

v² = u² + 2as

The equation v² = u² + 2as relates final velocity (v), initial velocity (u), acceleration (a), and displacement (s).

10 m/s

Using v = u + at, with u = 0, a = 2 m/s², t = 5 s, we get v = 0 + 2×5 = 10 m/s.

Acceleration

The slope of a velocity-time graph (Δv/Δt) represents the rate of change of velocity, which is acceleration.

Straight line with positive slope

Uniform acceleration means velocity changes at a constant rate, so the velocity-time graph is a straight line with a constant slope (positive if accelerating).

5 m/s²

Acceleration = (v - u) / t = (30 - 10) / 4 = 20 / 4 = 5 m/s².

g (downward)

When a stone is dropped, it falls under gravity, so its acceleration is g (approximately 9.8 m/s²) directed downward.

True

A horizontal line on a velocity-time graph indicates that velocity is constant over time, meaning zero acceleration.