A body moving with speed 10 m/s is stopped by applying constant braking power in 5 seconds. If the speed of the body is 30 m/s, then time in which the body can be stopped by applying the same retarding power is

(1)  10 s

(2)  15 s

(3)  30 s

(4)  45 s

A small ball is given a velocity $\sqrt{2gl}$ on the smooth horizontal floor which leads to a smooth vertical circular path. The ball will Smooth

(1)  complete the loop.

(2)  reach only up to point P.

(3)  reach to point Q.

(4)  leave the contact somewhere between P and Q.

A vertically compressed spring of constant k releases a ball of mass m as shown in the figure. The maximum height attained by the ball from the compressed point is (x is the initial compression in the spring)

1.  $\frac{{\mathrm{kx}}^2}{2\mathrm{mg}}$

2.  $\frac{{\mathrm{kx}}^2}{\mathrm{mg}}$

3.  $\frac{{\mathrm{kx}}^2}{4\mathrm{mg}}$

4.  $\frac{2{\mathrm{kx}}^2}{\mathrm{mg}}$

Work done the spring force in a time interval maybe

(1)  Positive

(2)  Negative

(3)  Zero

(4)  All of these

 A ball of mass m at rest starts moving from point A. The irregular surface is frictionless. The speed of the ball at the point C on the track is

1.  $\sqrt{\frac{4\mathrm{gH}}{3}}$

2.  $\sqrt{\frac{2\mathrm{gH}}{3}}$

3.  $\sqrt{\mathrm{gH}}$

4.  Zero

A ball is allowed to fall from a height of 10 m. If there is a 40% loss of energy due to impact, then after one impact ball will go up by

(1)  10 m

(2)  8 m

(3)  4 m

(4)  6 m

In a conservative field, work is done on a body by the field, then

(1)  The kinetic energy of the body definitely increases.

(2)  The kinetic energy of the body decreases.

(3)  The potential energy of the body increases.

(4)  Potential energy of the body decreases.

Work is done by an agent applying force when

(1)  the applied force is variable.

(2)  the applied force is perpendicular to the motion.

(3)  the applied force generate motion.

(4)  the applied force is constant.

A bob of a simple pendulum is released from position A. Velocity of the bob when it is at lowest position A is

(1)  $\sqrt{50}$ m/s

(2)  10 m/s

(3)  5 m/s

(4)  2$\sqrt{5}$ m/s