CBSE
Multiple Choice QuestionsA body of mass 1 kg is moving in a vertical circular path of radius 1 m. The difference between the kinetic energies at its highest and lowest position is :
20 J
10 J
10( - 1) J
A ball falling freely from a height of 4.9 m/s hits a horizontal surface. If e = ¾, then the ball will hit the surface second time after:
0.5 s
1.5 s
3.5 s
3.4 s
Two bodies of masses m and 2 m have equal kinetic energies. The ratio of their linear momenta is :
1
1/2
1/
2
Two bodies A and B have masses M and m respectively, where M > m and they are at a distance d apart. Equal force is applied to them so that they approach each other. The position where they hit each other is
nearer to B
nearer to A
at equal distance from A and B
Cannot be predicted
A body of mass m is moving towards the east and another body of equal mass is moving towards the north. If after collision both stick together, their speed after collision would be :
v
v/2
When a man increases his speed by 2 m/s, he finds that his kinetic energy is doubled, the original speed of the man is :
4.5 m/s
none of these
Hailstone at 0°C falls from a height of 1 km on an insulating surface converting the whole of its kinetic energy into heat. What part of it will melt? (g = 10 m/s2)
1/33
1/8
All of it will melt
A ball of mass m elastically collides with a wall with velocity 'v', then change in its momentum is equal to :
2m
2mv
+ 8mv
Zero
Two springs of force constant 1000 N/m and 2000 N/m are stretched by same, force. The ratio of their respective potential energies is
2 : 1
1 : 2
4 : 1
1 : 4
A particle rests on the top of a hemisphere of radius R. Find the smallest horizontal velocity that must be imparted to the particle, if it is to leave the hemisphere without sliding down it.
