Spring Force

Q.

A block of mass m is hanging from the ceiling by a spring whose spring constant is k. Now the spring is pulled further down by x units.

Find the spring force acting on the block at that instant?

Q.

Two blocks of unequal masses are tied by a spring. The blocks are pulled stretching the spring slightly and the system is released on a frictionless horizontal platform. Are the forces due to the spring on the two blocks equal and opposite? If yes, is it an example of Newton's third law?

1. Yes, No

2. Yes, Yes,

3. No, No

4. No, Yes

Q. A block $m_2$ is loaded onto another block $m_1$ placed on a spring of stiffness $k$ as shown in the figure. If block $m_2$ is suddenly removed, then magnitude of acceleration of block $m_1$ just after the removal of $m_2$ will be:

1. $\left(\frac{m_2}{m_1}g\right)$
2. $\frac{\sqrt{m_1{m}_2}}{m_1+m_{2}g}$
3. $\frac{m_1+m_2}{m_1-m_2}$
4. $\left(\frac{m_1}{m_2}g\right)$

Q. What is the extension in the spring? (Given spring constant= k, mass of man= m.)


reeeeles.

Q. The spring constant k is a property of only the material of a spring.

1. True
2. False

Q.

A spring balance A shows a reading of 2 kg, when an aluminium block is suspended from it. Another balance B shows a reading of 5 kg, when a beaker full of liquid is placed in its pan. The two balances are arranged such that the Al – block is completely immersed inside the liquid as shown in the figure. Then

1. The reading of the balance B will be less than 5 kg

2. The reading of the balance A will be less than 2 kg. and that of B will be more than 5 kg

3. The reading of balance A will be 2 kg. and that of B will be 5 kg.

4. The reading of the balance A will be more than 2 kg

Q. The masses of 10 kg and 20 kg respectively are connected by a massless spring as shown in figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration $12m/se{c}^2.$ What is the acceleration of 20 kg mass

1. 
2. 
3. 
4. 

Q. The extension in the spring is . (Given spring constant= k, mass of man= m.)

1. k/mg
2. 2kg/m
3. mg/k
4. Zero

Q. The spring constant k is a property of only the material of a spring.

1. True
2. False

Q. A 60 kg man stands on a spring scale in the lift. At some instant he finds, scale reading has changed from 60 kg to 50kg for a while and then comes back to the original mark. What should we conclude?

1. The lift was in constant motion downwards
2. The lift while in constant motion upwards, is stopped suddenly
3. The lift while in constant motion downwards, is suddenly stopped
4. The lift was in constant motion upwards