- 1(current)
Q. No.Given below are two statements:
| Assertion (A): | The net work done by gravity is equal to the loss in the vertical component of the kinetic energy for a projectile. |
| Reason (R): | The work-energy theorem applies to all systems including projectiles. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | (A) is false but (R) is true. |
A bullet of mass \(m\) fired at \(30^\circ\) to the horizontal leaves the barrel of the gun with a velocity \(v.\) The bullet hits a soft target at a height \(h\) above the ground while it is moving downward and emerge out with half the kinetic energy it had before hitting the target. Consider the following statements.
| a. | the velocity of the bullet will be reduced to half its initial value. |
| b. | the velocity of the bullet will be more than half of its earlier velocity. |
| c. | the bullet will continue to move along the same parabolic path. |
| d. | the bullet will move in a different parabolic path. |
| e. | the bullet will fall vertically downward after hitting the target. |
| f. | the internal energy of the particles of the target will increase. |
Which of the above-given statement(s) is/are correct in respect of the bullet after it emerges out of the target?
| 1. | (a), (c), (f) |
| 2. | (a), (d), (f) |
| 3. | (b), (d, (f) |
| 4. | (a), (b), (c) |
A woman pushes a trunk on a railway platform that has a rough surface. She applies a force of 100 N over a distance of 10 m. Thereafter, she gets tired and her applied force reduces linearly with distance to 50 N. The total distance through which the trunk has been moved is 20 m. The plot of force applied by the woman and the frictional force, which is 50 N versus displacement is given below. Work done by frictional force over the first 10 m will be:
1. -500 J
2. 500 J
3. 1000 J
4. -1000 J
| Assertion (A): | Work is energy transferred to or from an object by means of force acting on the object. |
| Reason (R): | If energy is transferred to the object, the work is positive and if the energy is transferred from the object, the work is negative work. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
- 1(current)
Q. No.
© 2024 GoodEd Technologies Pvt. Ltd.