Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
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 60 kg man skating at a speed of 10 m/s collides with a 40 kg...

A 60 kg60 \text{ kg} man skating at a speed of 10 m/s10 \text{ m/s} collides with a 40 kg40 \text{ kg} skater at rest, and they cling to each other. Determine the loss of kinetic energy during the collision.

Options

  1. A1800 J1800 \text{ J}
  2. B1200 J1200 \text{ J}
  3. C3000 J3000 \text{ J}
  4. D2400 J2400 \text{ J}

Correct answer

B. 1200 J1200 \text{ J}

Step-by-step solution

By the principle of conservation of linear momentum:

m1u1+m2u2=(m1+m2)vm_1 u_1 + m_2 u_2 = (m_1 + m_2) v

60×10+40×0=(60+40)v60 \times 10 + 40 \times 0 = (60 + 40) v

600=100v⇒v=6 m/s600 = 100 v \Rightarrow v = 6 \text{ m/s}

Initial kinetic energy of the system:

Ki=12m1u12=12×60×(10)2=3000 JK_i = \dfrac{1}{2} m_1 u_1^2 = \dfrac{1}{2} \times 60 \times (10)^2 = 3000 \text{ J}

Final kinetic energy of the system:

Kf=12(m1+m2)v2=12×100×(6)2=1800 JK_f = \dfrac{1}{2} (m_1 + m_2) v^2 = \dfrac{1}{2} \times 100 \times (6)^2 = 1800 \text{ J}

Loss of kinetic energy:

ΔK=Ki−Kf=3000−1800=1200 J\Delta K = K_i - K_f = 3000 - 1800 = 1200 \text{ J}
Practice Centre of Mass, Linear momentum, Collision on Quantrex Academy →

More from Centre of Mass, Linear momentum, Collision

As illustrated in the figure, a water molecule has a specific structure. Determine the… Concepts Of Physics MCQ Edition [Volume 1]A uniform disc of radius R is placed upon another uniform disc of radius 2R having the… Concepts Of Physics MCQ Edition [Volume 1]A disc of radius R is cut out from a larger disc of radius 2R such that the edge of the… Concepts Of Physics MCQ Edition [Volume 1]Three particles with masses of 1.0 kg , 2.0 kg and 3.0 kg are situated at the corners A… Concepts Of Physics MCQ Edition [Volume 1]Seven homogeneous bricks, each having a length L , are arranged as depicted in the… Concepts Of Physics MCQ Edition [Volume 1]A circular disc of diameter d and a square plate of edge d are placed touching each other… Concepts Of Physics MCQ Edition [Volume 1]Two blocks of masses 10 kg and 20 kg are located on the X -axis. The first mass is… Concepts Of Physics MCQ Edition [Volume 1]Determine the velocity of the centre of mass for the system of particles depicted in the… Concepts Of Physics MCQ Edition [Volume 1] Full Centre of Mass, Linear momentum, Collision list All Concepts Of Physics MCQ Edition [Volume 1] PYQs