Two blocks of masses \(2\) kg and \(3\) kg placed on a horizontal surface are connected by a massless string. If \(3\) kg is pulled by \(10\) N as shown in the figure, then the force of friction acting on the \(2\) kg block will be: [Take \(g=10~\text{m/s}^2\)]
1. | \(6\) N | 2. | \(4\) N |
3. | \(8\) N | 4. | \(12\) N |
Two plates of the same mass are attached rigidly to the two ends of a spring. One of the plates rests on a horizontal surface, and the other results in compression \(X\) of the spring when it is in steady-state. If an external force is applied to the upper plate to just lift off the lowest plate, what further compression in the spring is required?
1. | \(0.5X\) | 2. | \(3X\) |
3. | \(2X\) | 4. | \(X\) |
Two masses, \(M\) and \(m\), are connected by a weightless string. They are pulled by a force on a frictionless horizontal surface. The tension in the string will be:
1. \(\frac{F \left(M + 2 m\right)}{m + M}\)
2. \(F \over {m +M}\)
3. \(\frac{FM}{m}\)
4. \(Fm \over {m + M}\)
If the system shown in the figure is in equilibrium, then the reading of spring balance (in kgf) is:
1. \(10\)
2. \(20\)
3. \(100\)
4. zero
An impulse of \(6m \hat{j}\) is applied to a body of mass m moving with velocity \(\hat i+2\hat j\). The final velocity of the body will be:
1. \(-\hat i + 8\hat j\)
2. \(\hat i - 8\hat j\)
3. \(\hat i + 8\hat j\)
4. \(8\hat i - \hat j\)
A body is moving with a velocity of \(2\hat i\) m/s. If the force acting on the body is \((2\hat i+3\hat j+3\hat k)\) N, then the momentum of the body is changing in:
1. \(X\)-direction only
2. \(X\text-Y\) directions
3. \(Y\text-Z\) directions
4. In all \(X\text-Y\text-Z\) directions
A parachutist falls downward with an acceleration of \(2~\text{m/s}^2\) at a height of \(200\) m from the ground. Calculate the upthrust of air if the mass of the parachutist is \(60\) kg: (assume \(g= 10~\text{m/s}^2)\)
1. \(480\) N
2. \(620\) N
3. \(720\) N
4. \(600\) N
What is the minimum value of force \(F\) such that at least one block leaves the ground in the given figure? \(\left(g=10~\text{m/s}^2\right)\)
1. | \(20~\text{N}, 2~\text{kg}\) leaves the ground first. |
2. | \(30~\text{N}, 3~\text{kg}\) leaves the ground first. |
3. | \(40~\text{N}, 2~\text{kg}\) leaves the ground first. |
4. | \(50~\text{N}, 3~\text{kg}\) leaves the ground first. |
The block of mass m (shown in the figure) does not move on applying the inclined force \(F\). The friction force acting on the block is:
1. \(F \cos\theta\)
2. \(F \sin\theta\)
3. \(\mu mg-F \sin\theta\)
4. \(\mu mg\)
Fundamentally, the normal force between two surfaces in contact is:
1. Electromagnetic
2. Gravitational
3. Weak nuclear force
4. Strong nuclear force