back to directory
NEET PHYSICSWORK, ENERGY AND POWEREasy

Question

A bullet of mass mm hits a stationary block of mass MM elastically. The transfer of energy is the maximum, when:

A

M=mM = m

B

M=2mM = 2m

C

MmM \ll m

D

MmM \gg m

Step-by-Step Solution

  1. Analyze Elastic Collision: In a head-on elastic collision between a projectile of mass m1m_1 (bullet, mm) and a stationary target of mass m2m_2 (block, MM), kinetic energy is conserved.
  2. Energy Transfer: The fractional kinetic energy transferred from the projectile to the target is given by: KblockKbullet=4m1m2(m1+m2)2=4mM(m+M)2\frac{K_{block}}{K_{bullet}} = \frac{4m_1 m_2}{(m_1 + m_2)^2} = \frac{4mM}{(m + M)^2}
  3. Maximize Transfer: This fraction is maximum (equal to 1 or 100%) when the numerator equals the denominator, i.e., 4mM=(m+M)24mM = (m + M)^2, which simplifies to (Mm)2=0(M - m)^2 = 0, implying M=mM = m.
  4. NCERT Reference: This corresponds to Case I in the text: 'If the two masses are equal... The first mass comes to rest and pushes off the second mass with its initial speed on collision.' Thus, the entire kinetic energy is transferred [Class 11 Physics, Ch 5, Sec 5.11.2, Case I].

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from WORK, ENERGY AND POWER. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSWORK, ENERGY AND POWERbulletstationaryelasticallytransferenergy

More WORK, ENERGY AND POWER Questions

View all

A $100 \text{ g}$ iron ball having velocity $10 \text{ m/s}$ collides with a wall at an angle $30^\circ$ and rebounds with the same angle. If the period of contact between the ball and wall is $0.1 \text{ second}$, then the force experienced by the wall is:

A.$10 \text{ N}$
B.$100 \text{ N}$
C.$1.0 \text{ N}$
D.$0.1 \text{ N}$
MediumSolve

An object of mass $500 \text{ g}$ initially at rest is acted upon by a variable force whose $x$-component varies with $x$ in the manner shown. The velocities of the object at the points $x=8 \text{ m}$ and $x=12 \text{ m}$ would have the respective values of nearly:

A.18 m/s and 22.4 m/s
B.23 m/s and 22.4 m/s
C.23 m/s and 20.6 m/s
D.18 m/s and 20.6 m/s
MediumSolve

When a body moves with a constant speed along a circle

A.No work is done on it
B.No acceleration is produced in the body
C.No force acts on the body
D.Its velocity remains constant
EasySolve

Force $F$ on a particle moving in a straight line varies with distance $d$ as shown in the figure. The work done on the particle during its displacement of $12$ m is:

A.21 J
B.26 J
C.13 J
D.18 J
MediumSolve

A particle moves with a velocity $(5\hat i-3\hat j+6\hat k)\text{ ms}^{-1}$ horizontally under the action of a constant force $(10\hat i+10\hat j+20\hat k)\text{ N}$. The instantaneous power supplied to the particle is:

A.200 W
B.zero
C.100 W
D.140 W
EasySolve

In a circus stuntman rides a motorbike in a circular track of radius $R$ in the vertical plane. The minimum speed at highest point of track will be:

A.$\sqrt{2gR}$
B.$2gR$
C.$\sqrt{3gR}$
D.$\sqrt{gR}$
EasySolve

The minimum work done in pulling up a block of wood weighing $2 \text{ kN}$ for a length of $10 \text{ m}$ on a smooth plane inclined at an angle of $15^\circ$ with the horizontal is (given $\sin 15^\circ = 0.2588$):

A.$4.36 \text{ kJ}$
B.$5.17 \text{ kJ}$
C.$8.91 \text{ kJ}$
D.$9.82 \text{ kJ}$
EasySolve

A man fires a bullet of mass $200 \text{ g}$ at a speed of $5 \text{ m/s}$. The gun is of one kg mass. By what velocity the gun rebounds backwards?

A.$0.1 \text{ m/s}$
B.$10 \text{ m/s}$
C.$1 \text{ m/s}$
D.$0.01 \text{ m/s}$
EasySolve

This neet physics practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice physics sets →