Which of the diagrams shown in the figure represents the variation of to mechanical energy of a pendulum oscillating in the air as a function of time.
1. | 2. | ||
3. | 4. |
1. | 2. | ||
3. | 4. |
In a shotput event, an athlete throws the shotput of mass \(10\) kg with an initial speed of \(1\) m/s at \(45^\circ\) from a height \(1.5\) m above ground. Assuming air resistance to be negligible and acceleration due to gravity to be \(10\) m/, the kinetic energy of the shotput when it just reaches the ground will be:
1. \(2.5\) J
2. \(5.0\) J
3. \(52.5\) J
4. \(155.0\) J
1. | 2. | ||
3. | 4. |
A man of mass \(m,\) standing at the bottom of the staircase, of height \(L,\) climbs it and stands at its top.
(a) | work done by all forces on man is equal to the rise in energy \(mgL.\) |
(b) | work done by all forces on man is zero. |
(c) | work done by the gravitational force on man is \(mgL.\) |
(d) | the reaction force from a step does not do work because the point of the application of the force does not move while the force exists. |
Choose the correct option:
1. (a, d)
2. (a, c)
3. (b, d)
4. (a, b, c)
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) |