A simple pendulum hangs from the roof of a train moving on horizontal rails. If the string is inclined towards the front of the train, then train is-

1. Moving with constant velocity

2. In accelerated motion

3. In retarded motion

4. At rest

When a 5 kg plastic box is placed deep inside water, it accelerates up at a rate of g/6. How much sand should be put inside the box so that it may accelerate down at the rate of g/6?

The graph for stopping time (t) versus mass (m) is shown in the figure. Then which one of the pairs is given?

1.  Momentum, force

2.  K.E., force

3.  Velocity, force

4.  None of these

Tension on the string at point P is T. The graph for tension (T) versus x is shown in the figure. Then the string is:

1.  massless

2.  massfull

3.  tension on every point on the string is same when the string is having finite mass 4

4.  None of these

While walking on ice one should take small steps to avoid slipping. This is because smaller steps ensure

1. Larger friction

2. Smaller friction

3. Larger normal force

4. Smaller normal force

A block is kept on a rough inclined plane with angle of inclination $\theta$. The graph of net reaction (R) versus $\theta$ is:

1. 

2. 

3. 

(4) None of these

A block is placed on a rough horizontal plane. A time dependent horizontal force F=kt acts on the block. The acceleration time graph of the block is :

1. 

2. 

3. 

4. 

A rod of length L and mass m is acted on by two unequal forces $F_1$ and $F_2\left(<F_1\right)$ as shown in the following figure

The tension in the rod at a distance y from the end A is given by :

1. $F_1\left(1-\frac{y}{L}\right)+F_2\left(\frac{y}{L}\right)$

2. $F_2\left(1-\frac{y}{L}\right)+F_1\left(\frac{y}{L}\right)$

3. $\left(F_1-F_2\right)\frac{y}{L}$

4. None of the above

Two blocks A and B of masses m & 2m respectively are held at rest such that the spring is in natural length. Find the accelerations of both the blocks just after release.

(1) $g\downarrow , g\downarrow$

(2) $\frac{g}{3}\downarrow , \frac{g}{3}\uparrow$

(3) (0, 0)

(4) $g\downarrow , 0$

Two blocks 'A' and 'B' each of mass 'm' are placed on a smooth horizontal surface. Two horizontal force F and 2F are applied on both the blocks 'A' and 'B' respectively as shown in figure. The block A does not slide on block B. Then the normal reaction acting between the two blocks is:

(1) F

(2) F/2

(3) $\frac{F}{\sqrt{3}}$

(4) 3F