A block of mass kg, moving in the direction with a constant speed of ms-1, is subjected to a retarding force J/m during its travel from m to m. Its final kinetic energy will be:
1. | J | 2. | J |
3. | J | 4. | J |
1. | 2. | ||
3. | 4. |
A body of mass m dropped from a height h reaches the ground with a speed of 1.4. The work done by air drag is:
1. –0.2mgh
2. –0.02mgh
3. –0.04mgh
4. mgh
A force of 5 N making an angle with the horizontal acting on an object displaces it by 0.4 m along the horizontal direction. If the object gains kinetic energy of 1 J then the component of the force is:
1. | 1.5 N | 2. | 2.5 N |
3. | 3.5 N | 4. | 4.5 N |
The energy required to accelerate a car from rest to 30 m/s is E. The energy required to accelerate the car from 30 m/s to 60 m/s will be:
1. | E | 2. | 2E |
3. | 3E | 4. | 4E |
According to the work-energy theorem, the change in kinetic energy of a body is equal to work done by:
1. Non-conservative force on the particle
2. Conservative force on the particle
3. External force on the particle
4. All the forces on the particle
A block is carried slowly up an inclined plane. If is work done by the friction, is work done by the reaction force, is work done by the gravitational force, and is the work done by an external force, then choose the correct relation(s):
1.
2.
3.
4. All of these
A particle of mass kg moves with a velocity of in SI units, where is displacement. The work done by the net force during the displacement of the particle from to is:
1.
2.
3.
4.
A block is released from rest from a height of After traveling through the smooth curved surface, it moves on the rough horizontal surface through a length and climbs onto the other smooth curved surface at a height If then the height is:
1. | 2. | ||
3. | 4. | Zero |
A man pushes a wall and fails to displace it. He does:
1. negative work
2. positive but not maximum work
3. no work at all
4. maximum work