1. | \(7.5~\text m\) | 2. | \(10~\text m\) |
3. | \(2.5~\text m\) | 4. | \(5~\text m\) |
A mass \(m\) is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when:
1. | \(60^{\circ}\) from vertical. | inclined at an angle of
2. | the mass is at the highest point. |
3. | the wire is horizontal. |
4. | the mass is at the lowest point. |
A body initially at rest and sliding along a frictionless track from a height \(h\) (as shown in the figure) just completes a vertical circle of diameter \(\mathrm{AB}= D.\) The height \({h}\) is equal to:
1. \({3\over2}D\)
2. \(D\)
3. \({7\over4}D\)
4. \({5\over4}D\)
What is the minimum velocity with which a body of mass \(m\) must enter a vertical loop of radius \(R\) so that it can complete the loop?
1. \(\sqrt{2 g R}\)
2. \(\sqrt{3 g R}\)
3. \(\sqrt{5 g R}\)
4. \(\sqrt{ g R}\)
A ball is thrown vertically downward from a height of \(20\) m with an initial velocity \(v_0\). It collides with the ground, loses \(50\%\) of its energy in a collision, and rebounds to the same height. The initial velocity \(v_0\) is:
(Take, \(g=10~\mathrm{ms^{-2}}\))
1. \(14\) ms–1
2. \(20\) ms–1
3. \(28\) ms–1
4. \(10\) ms–1