Water falls from a height of 60 m at the rate of 15kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine? (Take g = 10 m/s2)
8.1 kW
10.2 kW
12.3 kW
7.0 kW
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
1
A stone is thrown at an angle of 45o to the horizontal with kinetic energy K. The kinetic energy at the highest point is
K
zero
300 J of work is done in sliding a 2kg block up an inclined plane of height 10 m. Taking g = 10 m/s2, work done against friction is
200 J
100 J
1000J
The identical balls A and B moving with velocities + 0.5 m/s and -0.3 m/s respectively collide head on elastically. The velocity of the balls A and B after collision will be respectively
+ 0.5 m/s and +0.3 m/s
-0.3 m/s and +0.5 m/s
+0.3 m/s and 0.5 m/s
-0.5 m/s and +0.3 m/s
If the momentum of a body is increased by 150% then the percentage increase in its kinetic energy is
50%
100%
125%
200%
The coefficient of restitution e for a perfectly elastic collision
infinite
-1
A position dependent force F=(7–2x + 3x2) N acts on a small body of mass 2 kg and displaces it from x = 0 to x = 5m.
Work done in joule is
35
70
135
270
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
If kinetic energy of a body is increased by 300% then the percentage change in momentum will be
150%
265%
73.2%
