JEE Advanced 2014 Paper 2 Physics Q19

Physics · Laws of Motion

Problem

A block of mass

m_1=1\,\mathrm{kg}

and another mass

m_2=2\,\mathrm{kg}

are placed together (see figure) on an inclined plane with angle of inclination

\theta

. Various values of

\theta

are given in List I. The coefficient of friction between block

m_1

and the plane is always zero. The coefficients of static and dynamic friction between block

m_2

and the plane are equal to

\mu=0.3

. In List II expressions for the friction on block

m_2

are given. Match the correct expression with the angles. The acceleration due to gravity is denoted by

g

. [Useful information:

\tan(5.5^\circ)\approx0.1

;

\tan(11.5^\circ)\approx0.2

;

\tan(16.5^\circ)\approx0.3

.] Column I — P:

\theta=5^\circ

; Q:

\theta=10^\circ

; R:

\theta=15^\circ

; S:

\theta=20^\circ

Column Ii — 1:

m_2g\sin\theta

; 2:

(m_1+m_2)g\sin\theta

; 3:

\mu m_2g\cos\theta

; 4:

\mu(m_1+m_2)g\cos\theta