A ball of mass 2 kg and another of mass 4kg are dropped together from a 60 ft tall building. After a fall of 30 ft each towards earth, their respective kinetic energies will be in the ratio of
1 : 4
1 : 2
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
Send is being dropped on a conveyor belt at the rate of M kg/s. The force necessary to keep the belt moving with a constant velocity of v m/s will be
Mv Newton
2Mv Newton
zero
An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of water jet. What is the rate at which kinetic energy is imparted to water?
½ mv3
mv3
½ mv2
½ m2v2
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
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
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
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
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.
The coefficient of restitution e for a perfectly elastic collision
infinite
-1
