If a young man of mass \(60\) kg stands on the floor of a lift which is accelerating downwards at \(1~\text{m/s}^2\), then the reaction of the floor of the lift on the man will be: \(\left(g = 9.8~\text{m/s}^2 \right)\)

1.	\(528\) N	2.	\(540\) N
3.	\(546\) N	4.	None of these

If $\mathrm{\mu }$ between block A and inclined plane is 0.5 and that between block B and the inclined plane is 0.8, then the normal reaction between blocks A and B will be:
                     
1. 180 N

2. 216 N

3. 0

4. None of these

A particle is on a smooth horizontal plane. A force \(F\) is applied, whose \(F\text-t\) graph is given.

Consider the following statements.

Select the correct statement(s):

A coin placed on a rotating table just slips if it is placed at a distance 4r from the center. On doubling the angular velocity of the table, the coin will just slip when the distance from the centre is equal to:-

1. 4r

2. 2r

3. r

4. $\frac{\mathrm{r}}{4}$

A massless string of length 1 m fixed at one end carries a mass of 2 kg at the other end. The string makes $\frac{2}{\mathrm{\pi }}$ rev/s around the axis through the fixed end as shown in the figure. The tension on the string will be:
            

Three blocks A, B and C of mass 3M, 2M and M respectively are suspended vertically with the help of springs PQ and TU and a string RS as shown in fig. The acceleration of blocks A, B and C are $a_1,a_2 and a_3$ respectively.
     

The value of acceleration \(a_{1}\) at the moment string RS is cut will be: 

1. g downward

2. g upward

3. more than g downward

4. zero

Two bodies of mass, \(4~\text{kg}\) and \(6~\text{kg}\), are tied to the ends of a massless string. The string passes over a pulley, which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity (\(g\)) is:

In the diagram, a \(100\) kg block is moving up with constant velocity. Find out the tension at point \(P\).

      
1. \(1330\) N
2. \(490\) N
3. \(1470\) N
4. \(980\) N

Calculate the reading of the spring balance shown in the figure: (take \(g=10\) m/s²)
                

1. \(60\) N
2. \(40\) N
3. \(50\) N
4. \(80\) N

An object of mass m is held against a vertical wall by applying horizontal force F as shown in the figure. The minimum value of the force F will be: (Consider friction between wall and object.)

   
1. Less than mg
2. Equal to mg
3. Greater than mg
4. Cannot determine