A body of mass 2 kg ,moving on a horizontal surface with an initial velocity of 4 m/s , comes to rest after 2s.If one wants to keep this moving on the same surface with a velocity of 4 m/s,the force required is
2 N
4 N
6 N
10 N
A man of 50 kg mass is standing in a gravity free space at a height of 10 m above the floor. He throws a stone of 0.5 kg mass downwards with a speed 2m/s. When the stone reaches the floor, the distance of the man above the floor will be
9.9 m
10.1 m
10 m
20 m
On the centre of frictionless table a small hole is made, through which a weightless string of length 2 l is inserted. On the two ends of the string two balls of the same mass m are attached. Arrangement is made in such a way that half of the string is on the table top and half is hanging below. The ball on the table top is made to move in a circular path with a constant speed v. What is the centripetal acceleration of the moving ball?
mvl
g
zero
2 mvl
A body of mass 2 kg begins to slide down a plane inclined at an angle of 450 with the horizontal. The force of friction will be
19.6 sin450
9.8 sin450
19.6 cos50
9.8 cos450
A body of mass 3 kg hits a wall at an angle of 600 and returns at the same angle. The impact time was 0.2 sec. The force exerted on the wall
100 N
Phyiscal independence of force is a consequence of
third law of motion
second law of motion
first law of motion
all of these laws
If μs is coefficient of static friction and μk is coefficient of kinetic friction, then
there is no relation between μs and μk
generally μs>μk
generally, μs=μk
generally μsk
When a bullet of mass 5kg is fired, the impulse on it is 200Ns. If the mass of the gun is 10kg, then the recoil velocity of the gun is
20ms-1
2ms-1
0.2ms-1
0.02ms-1
A ball of mass 25 g, moving with a velocity of 2 ms-1 is stopped within 5 cm. The average resistance offered to the ball is
5 N
1 N
When milk is churned, cream gets seperated due to
Centripetal force
Centrifugal force
Frictional force
Gravitational force
