back to directory
NEET PHYSICSLAWS OF MOTIONEasy

Question

A block BB is pushed momentarily along a horizontal surface with an initial velocity vv. If μ\mu is the coefficient of sliding friction between BB and the surface, the block BB will come to rest after a time:

A

vμg\frac{v}{\mu g}

B

μgv\frac{\mu g}{v}

C

gv\frac{g}{v}

D

vg\frac{v}{g}

Step-by-Step Solution

  1. Identify Forces: The block moves horizontally. The vertical forces are weight (mgmg) downwards and normal reaction (NN) upwards. Since there is no vertical motion, N=mgN = mg.
  2. Frictional Force: The sliding (kinetic) friction force fkf_k opposes the motion. The magnitude is given by fk=μN=μmgf_k = \mu N = \mu mg [NCERT Class 11, Physics Part I, Section 5.9].
  3. Determine Retardation: According to Newton's Second Law (F=maF = ma), the retardation aa (negative acceleration) caused by friction is: ma=fk=μmgma = -f_k = -\mu mg a=μga = -\mu g
  4. Kinematics: Use the first equation of motion vf=vi+atv_f = v_i + at to find the time tt when the block comes to rest (vf=0v_f = 0). 0=v+(μg)t0 = v + (-\mu g)t μgt=v\mu g t = v t=vμgt = \frac{v}{\mu g} (Reference: NCERT Class 11, Physics Part I, Chapter 5, Laws of Motion).

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from LAWS OF MOTION. 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.

PHYSICSLAWS OF MOTIONpushedmomentarilyhorizontalsurfaceinitial

More LAWS OF MOTION Questions

View all

A block A of mass $m_1$ rests on a horizontal table. A light string connected to it passes over a frictionless pulley at the edge of the table and from its other end, another block B of mass $m_2$ is suspended. The coefficient of kinetic friction between block A and the table is $\mu_k$. When block A is sliding on the table, the tension in the string is:

A.$\frac{(m_2 + \mu_k m_1)g}{(m_1 + m_2)}$
B.$\frac{(m_2 - \mu_k m_1)g}{(m_1 + m_2)}$
C.$\frac{m_1 m_2 (1 - \mu_k)g}{(m_1 + m_2)}$
D.$\frac{m_1 m_2 (1 + \mu_k)g}{(m_1 + m_2)}$
MediumSolve

A block of mass 4 kg is suspended through two light spring balances A and B connected in series. Then A and B will read respectively:

A.4 kg and 0 kg
B.0 kg and 4 kg
C.4 kg and 4 kg
D.2 kg and 2 kg
EasySolve

A lift of mass $1000 \text{ kg}$ is moving with an acceleration of $1 \text{ m/s}^2$ in the upward direction. Tension developed in the string, which is connected to the lift, is:

A.9,800 N
B.10,000 N
C.10,800 N
D.11,000 N
EasySolve

The distance covered by a body of mass $5 \text{ g}$ having linear momentum $0.3 \text{ kg m/s}$ in $5 \text{ s}$ is:

A.300 m
B.30 m
C.3 m
D.0.3 m
EasySolve

A particle of mass $m$ is projected with velocity $v$ making an angle of $45^\circ$ with the horizontal. When the particle lands on the level ground, the magnitude of the change in its momentum will be:

A.$2mv$
B.$mv/\sqrt{2}$
C.$mv\sqrt{2}$
D.zero
EasySolve

It is easier to draw up a wooden block along a smooth inclined plane than to haul it vertically, principally because:

A.The friction is reduced
B.The mass becomes smaller
C.Only a part of the weight has to be overcome
D.‘g’ becomes smaller
EasySolve

When two surfaces are coated with a lubricant, then they:

A.Stick to each other
B.Slide upon each other
C.Roll upon each other
D.None of these
EasySolve

A block of mass $m$ is in contact with the cart $C$ as shown in the figure. The coefficient of static friction between the block and the cart is $\mu$. The acceleration $a$ of the cart that will prevent the block from falling satisfies:

A.$a > \frac{mg}{\mu}$
B.$a > \frac{g}{\mu m}$
C.$a \ge \frac{g}{\mu}$
D.$a < \frac{g}{\mu}$
MediumSolve

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 →