Laws of Motion · Question 62

An object of mass 3 kg is at rest. Now a force of F = 6t2 i + 4t j is applied on the object then velocity of object at t = 3 sec. is

1. 18 i + 3 j
2. 18 i + 6 j
3. 3 i + 18 j
4. 18 i + 4 j

A lift of mass 1000 kg which is moving with acceleration of 1 m/s2 in upward direction, then the tension developed in string which is connected to lift is

1. 9800 N
2. 10,800 N
3. 11,000 N
4. 10,000 N

A block of mass 10 kg placed on rough horizontal surface having coefficient of friction = 0.5, if a horizontal force of 100 N acting on it then acceleration of the block will be

1. 10 m/s2
2. 5 m/s2
3. 15 m/s2
4. 0.5 m/s2

On the horizontal surface of a truck a block of mass 1 kg is placed ( = 0.6) and the truck is moving with acceleration 5 m/s2, then the frictional force on the block will be

1. 5 N
2. 6 N
3. 5.88 N
4. 8 N

A cricketer catches a ball of mass 150 g in 0.1 s moving with speed 20 m/s, then he experiences a force of

1. 300 N
2. 30 N
3. 3 N
4. 0.3 N

A 1 kg stationary bomb is exploded in three parts having mass 1 : 1 : 3 respectively. The parts having the same mass move in perpendicular directions with velocity 30 m/s, then the velocity of the bigger part will be

1. 10 2 m/s
2. 10 2 m/s
3. 15 2 m/s
4. 15 2 m/s

A body of mass 3 kg hits a wall at an angle of 60 and returns at the same angle. The impact time was 0.2 s. The force exerted on the wall is [figure]

1. 150 3 N
2. 50 3 N
3. 100 N
4. 75 3 N

Two masses as shown in the figure are suspended from a massless pulley. The acceleration of the system when masses are left free is [figure]

1. 2g3
2. g3
3. g9
4. g7

A mass of 1 kg is thrown up with a velocity of 100 m/s. After 5 seconds, it explodes into two parts. One part of mass 400 g comes down with a velocity 25 m/s. The velocity of other part is (Take g = 10 m s-2)

1. 40 m/s
2. 50 m/s
3. 100 m/s
4. 60 m/s