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
For a satellite moving in an orbit around the earth, the ratio of kinetic energy to potential energy is
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
A.
0.4 cm
The situation can be shown as: Let radius of complete disc is a and that of small disc is b. Also let centre of mass now shifts to 02 at a distance X2 from original centre
The position of new centre of mass is given by
Here, a = 6 cm, b = 2 cm, x1 = 3.2 cm
⇒ XCM = 0.4 cm
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