A ball of mass 50 g travelling at a speed of 2.0 m/s strikes a plane surface at an angle of incidence 45^ ^ ^ . The ball is reflected by the plane at an equal angle of reflection with the same speed. Determine the

Correct answer: D. 0 kg-m/s Mass of the ball, m = 50 g = 0.05 kg Initial speed of the ball, v_i = 2.0 m/s Final speed of the ball, v_f = 2.0 m/s The magnitude of the initial momentum is: | p _i| = m v_i = 0.05 × 2.0 = 0.10 kg-m/s The magnitude of the final momentum is: | p _f| = m v_f = 0.05 × 2.0 = 0.10 kg-m/s The change in the magnitude of the momentum is the difference between the final and initial magnitudes of momentum: Δ | p | = | p _f| - | p _i| = 0.10 - 0.10 = 0 kg-m/s

Concepts Of Physics MCQ Edition [Volume 1]

Exam: Concepts Of Physics MCQ Edition [Volume 1]
Subject: Physics
Chapter: Centre of Mass, Linear momentum, Collision

Concepts Of Physics MCQ Edition [Volume 1] · Physics · Centre of Mass, Linear momentum, Collision

A ball of mass 50 g travelling at a speed of 2.0 m/s strikes a...

A ball of mass

50 \text{ g}

travelling at a speed of

2.0 \text{ m/s}

strikes a plane surface at an angle of incidence

45^{}^{{}^{\circ}}

. The ball is reflected by the plane at an equal angle of reflection with the same speed. Determine the change in the magnitude of the momentum of the ball.

Options

A $0.10 \text{ kg-m/s}$
B $0.14 \text{ kg-m/s}$
C $0.20 \text{ kg-m/s}$
D $0 \text{ kg-m/s}$

Correct answer

D. $0 \text{ kg-m/s}$

Step-by-step solution

Mass of the ball,

m = 50 \text{ g} = 0.05 \text{ kg}

Initial speed of the ball,

v_i = 2.0 \text{ m/s}

Final speed of the ball,

v_f = 2.0 \text{ m/s}

The magnitude of the initial momentum is:

|\vec{p}_i| = m v_i = 0.05 \times 2.0 = 0.10 \text{ kg-m/s}

The magnitude of the final momentum is:

|\vec{p}_f| = m v_f = 0.05 \times 2.0 = 0.10 \text{ kg-m/s}

The change in the magnitude of the momentum is the difference between the final and initial magnitudes of momentum:

\Delta |\vec{p}| = |\vec{p}_f| - |\vec{p}_i| = 0.10 - 0.10 = 0 \text{ kg-m/s}

Practice Centre of Mass, Linear momentum, Collision on Quantrex Academy →

More from Centre of Mass, Linear momentum, Collision