The coefficient of restitution e for a perfectly elastic collision
1
zero
infinite
-1
A bullet of mass 10g leaves a rifle at an initial velocity of 1000m/s and strike the earth at the same level with a velocity of 500m/s. The work done in joule to overcome the resistance of air will be
375
3750
5000
500
A child swinging a swing. Minimum and maximum heights of swing from earth’s surface are 0.75 m and 2m respectively. The maximum velocity of this swing is
5 m/s
10 m/s
15 m/s
20 m/s
Two masses 1g and 9g are moving with equal kinetic energies. The ratio of the magnitudes of their respective linear momenta is
1 : 9
9 : 1
1 : 3
3 : 1
A stationary particle explodes into two particles of masses m1 and m2 which move in opposite directions with velocities v1 ad v2. The ratio of their kinetic energies E1 / E2 is
A shell of mass 200 gm is ejected from a gun of mass 4kg by an explosion that generates 1.05 kJ of energy. The initial velocity of the shell is
100 ms-1
80 ms-1
40 ms-1
120 ms-1
If the momentum of a body is increased by 150% then the percentage increase in its kinetic energy is
50%
100%
125%
200%
A bomb of mass 30kg at rest explodes into two pieces of masses 18kg ad 12kg. The velocity of 18kg mass is 6ms-1. The kinetic energy of the other mass is
256 J
486 J
524 J
324 J
Two bodies with kinetic energies in the ratio 4 : 1 are moving with equal linear momentum. The ratio of their masses is
1 : 2
1 : 1
4 : 1
1 : 4
A body of mass 1kg is thrown upward with a velocity 20 ms-1.It momentarily comes to rest after attaining a height of 18m. How much energy is lost due to air friction ? ( g = 10 ms-2)
20 J
30 J
40 J
10 J.
