Q61 of 146 Page 148

In case of negative work, the angle between the force and displacement is:

A. 0o B. 45o


C. 90o D. 180o

Since, in order to have the negative work the direction of force applied and the direction of the displacement must be in opposite direction.

More from this chapter

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59

A car is accelerated on a leveled road and acquires a velocity 4 times of its initial velocity. During this process, the potential energy of the car:

A. Does not change


B. Becomes twice that of initial potential energy


C. Becomes 4 times that of initial potential energy


D. Becomes 16 times that of initial potential energy.

 60

A car is accelerated on a leveled road and attains a speed of 4 times its initial speed. In this process, the kinetic energy of the car:

A. Does not change


B. Becomes 4 times that of initial kinetic energy


C. Becomes 8 times that of initial kinetic energy


D. Becomes 16 times that of initial kinetic energy

 62

An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass 3.5 kg. Both the spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same:

A. Acceleration


B. Momentum


C. Potential energy


D. Kinetic energy

 63

A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a leveled road. If the value of g be 10 m/s2, the work done by the girl against the gravitational force will be:

A. 6000 J B. 0.6 J


C. 0 J D. 6 J