A ball is dropped from the top of a building of height 80 m. At the same instant, another ball is thrown upwards with a speed 50 m/s from the bottom of the building. The time at which balls will meet is-

(1) 1.6 s

(2) 5 s

(3) 8 s

(4) 10 s

An unloaded bus can be stopped by applying brakes on straight road after covering a distance x. Suppose, the passenger add 50% of its weight as the load and the braking force remains unchanged, how far will the bus go after the application of the brakes? (Velocity of bus in both case is same)

1. Zero

2. 1.5x

3. 2x

4. 2.5x

Figure below shows the velocity-time graph. This graph tells us that the body is:

1. Starting from rest and moving with increasing acceleration

2. Moving with uniform speed.

3. Moving with uniform acceleration.

4. Moving with decreasing acceleration.

In the following velocity-time graph of a body, the distance and displacement traveled by the body in 5 seconds in metres will be, respectively:

1. 75, 115

2. 110, 70

3. 45, 75

4. 95, 55

A body is thrown upwards and reaches its maximum height. At that position:

Two cars A and B are moving in the same direction with velocities 30 m/s and 20 m/s. When car A is at a distance d behind the car B, the driver of the car A applies brakes producing uniform retardation of 2 m/s². There will be no collision when

(1) d < 2.5 m

(2) d > 125 m

(3) d > 25 m

(4) d < 125 m

Two cars are moving in the same direction with a speed of 30 km/h. They are separated from each other by 5 km. The third car moving in the opposite direction meets the two cars after an interval of 4 minutes. The speed of the third car is

(1) 30 km/h

(2) 25 km/h

(3) 40 km/h

(4) 45 km/h

A train of 150 m length is going towards North a speed of 10 m/s. A bird is flying at 5 m/s parallel to the track towards the South. The time taken by the to the track bird to cross the train is

(1) 10 s

(2) 15 s

(3) 30 s

(4) 12 s

A boat covers certain distance between two spots in a river taking t₁ hrs going downstream and t₂ hrs going upstream. What time will be taken by boat to cover same distance in still water?

(1) $\frac{t_1+t_2}{2}$

(2) $2\left(t_2-t_1\right)$

(3) $\frac{2t_1{t}_2}{t_1+t_2}$

(4) $\sqrt{t_1{t}_2}$

The position \((x)\)-time \((t)\) graph for a particle moving along a straight line is shown in the figure. The average speed of particle in time interval \(t=0\) to \(t=8\text{ s}\) is:

 
1. zero
2. \(5~\text{m/s}\)
3. \(7.5~\text{m/s}\)
4. \(9.7~\text{m/s}\)