For inelastic collision between two spherical rigid bodies

• the total kinetic energy is conserved

• the total mechanical energy is not conserved

• the linear momentum is not conserved

• the linear momentum is conserved

2.

For a satellite moving in an orbit around the earth, the ratio of kinetic energy to potential energy is

• 2

• $\frac{1}{2}$

• $\frac{1}{\sqrt{2}}$

• $\sqrt{2}$

300 J of work is done in sliding a 2 kg block up an inclined plane of height 10 m. Taking g =10 m/s², work done against friction is

• 200J

• 100 J

• zero

• 1000 J

A particle moves along a straight line OX. At a time t (in second) the distance x ( in metre ) of the particle from O is given by x = 40 + 12 t - t³ . How long would the particle travel before coming to rest?

• 24 m

• 40 m

• 56 m

• 16 m

A small disc of radius 2 cm is cut from a disc of radius 6 cm. If the distance between their centres is 3.2 cm, what is the shift in the centre of mass of the disc?

• 0.4 cm

• 2.4 cm

• 1.8 cm

• 1.2 cm

The displacement of particle is given by $\mathrm{x} = {\mathrm{\alpha }}_{\mathrm{o}}+ \frac{{\mathrm{\alpha }}_1\mathrm{t}}{2} - \frac{{\mathrm{\alpha }}_2{\mathrm{t}}^2}{3}$ .What is its acceleration?

• $\frac{2{\mathrm{\alpha }}_2}{3}$

• $-\frac{2{\mathrm{\alpha }}_2}{3}$

• ${\mathrm{\alpha }}_2$

• Zero

The area of the acceleration-displacement curve of a body gives

• impulse

• change in momentum per unit mass

• change in KE per unit mass

• total change in energy

The speed of earth's rotation about its axis is o. Its speed is increased to x times to make the effective acceleration due to gravity equal to zero at the equator. Then x is

• 1

• 8.5

• 17

• 34

A projectile is thrown in the upward direction making an angle of 60° with the horizontal direction with a velocity of 147 ms^-1 Then the time after which its inclination with the horizontal is 45°, is

• 15 s

• 10.98 s

• 5.49 s

• 2.745 s

A motor cycle is going on an overbridge of radius R. The driver maintains a constant speed. As the motor cycle is ascending on the overbridge, the normal force on it

• increases

• decreases

• remains the same

• fluctuates erratically