The upper half of an inclined plane with inclination $\phi$ is perfectly smooth, while the lower half is rough. $A$ body starting from rest at the top will again come to rest at the bottom, if the coefficient of friction for the lower half is given by-
$2 \sin \phi$
$2 \cos \phi$
$2 \tan \phi$
$ \tan \phi$
Two particles of masses $m_1, m_2$ move with initial velocities $u_1$and $u_2$ On collision, one of the particles get excited to higher level, after absorbing energy $\varepsilon $. If final velocities of particles be $v_1$ and $v_2$ then we must have
A projectile is fired at a speed of $100\, m/sec$ at an angle of $37^o$ above the horizontal. At the highest point, the projectile breaks into two parts of mass ratio $1:3$ , the smaller coming to rest. Then the distance of heavier part from the launching point is ............... $\mathrm{m}$
A body of mass $50\, kg$ is projected vertically upwards with velocity of $100 \,m/sec$. $5 \,seconds$ after this body breaks into $20\, kg$ and $30 \,kg$. If $20\, kg $ piece travels upwards with $150 \,m/sec$, then the velocity of other block will be
$A$ block of mass $m$ starts from rest and slides down $a$ frictionless semi-circular track from $a$ height $h$ as shown. When it reaches the lowest point of the track, it collides with a stationary piece of putty also having mass $m$. If the block and the putty stick together and continue to slide, the maximum height that the block-putty system could reach is:
A particle of mass m moving with velocity ${V_0}$ strikes a simple pendulum of mass $m$ and sticks to it. The maximum height attained by the pendulum will be