A bullet of mass \(0.04~\text{kg}\) moving with a speed of \(90~\text{m/s}\) enters a heavy fixed wooden block and is stopped after a distance of \(60~\text{cm}\). The average resistive force exerted by the block on the bullet is:
1. | \(0~\text{N}\) | 2. | \(270~\text{N}\) |
3. | \(370~\text{N}\) | 4. | \(290~\text{N}\) |
The motion of a particle of mass \(m\) is described by \(y=ut+\frac{1}{2}gt^{2}.\) The force acting on the particle is:
1. \(3mg\)
2. \(mg\)
3. \(\frac{mg}{2}\)
4. \(2mg\)
See the figure given below. A mass of \(6\) kg is suspended by a rope of length \(2\) m from the ceiling. A force of \(50\) N is applied at the mid-point \(P\) of the rope in the horizontal direction, as shown. What angle does the rope make with the vertical in equilibrium? (Take \(g=10~\text{ms}^{-2}\)). Neglect the mass of the rope.
1. | \(90^\circ\) | 2. | \(30^\circ\) |
3. | \(40^\circ\) | 4. | \(0^\circ\) |
What is the acceleration of the block and tension in the string of the block and trolley system shown in a figure, if the coefficient of kinetic friction between the trolley and the surface is \(0.04\)? (Take \(g=10~\mathrm{m/s^2}\)). Neglect the mass of the string.
1. | \(9.6~\mathrm{m/s^2}\) and \(27.1~\mathrm{N}\) | 2. | \(9.6~\mathrm{m/s^2}\) and \(2.71~\mathrm{N}\) |
3. | \(0.96~\mathrm{m/s^2}\) and \(27.1~\mathrm{N}\) | 4. | \(0.63~\mathrm{m/s^2}\) and \(30~\mathrm{N}\) |
In the figure given below, a wooden block of mass \(2\) kg rests on a soft horizontal floor. When an iron cylinder of mass \(25\) kg is placed on top of the block, the floor yields steadily and the block and the cylinder together go down with an acceleration of \(0.1~\mathrm{m/s^2}\). What is the force of the block on the floor after the floor yields? (Take \(g=10~\mathrm{m/s^2}\).)
1. \(270\) N upward
2. \(267.3\) N downward
3. \(20\) N downward
4. \(267.3\) N upward