A body dropped from a height h with an initial speed of zero, strikes the ground with a velocity $3km/h$. Another body of the same mass is dropped from the same height h with an initial speed $-u^{\text{'}}=4km/h$. Find the final velocity of the second body with which it strikes the ground.

1. 3 km/h

2. 4 km/h

3. 5 km/h

4. 12 km/h

A ball of mass m₁ and another ball of mass m₂ are dropped from equal height. If time taken by the balls are t₁ and t₂ respectively, then 

1. $t_1=\frac{t_2}{2}$

2. $t_1=t_2$

3. $t_1=4t_2$

4. $t_1=\frac{t_2}{4}$ 

With what velocity a ball be projected vertically so that the distance covered by it in 5^th second is twice the distance it covers in its 6^th second $(g=10m/s^2)$ 

1. 58.8 m/s

2. 49 m/s

3. 65 m/s

4. 19.6 m/s

A ball is dropped downwards. After 1 second another ball is dropped downwards from the same point. What is the distance between them after 3 seconds 

1.  25 m
2.  20 m
3.  50 m
4.  9.8 m

A stone is thrown with an initial speed of 4.9 m/s from a bridge in vertically upward direction. It falls down in water after 2 sec. The height of the bridge is 

1. 4.9 m

2. 9.8 m

3. 19.8 m

4. 24.7 m

A stone is shot straight upward with a speed of 20 m/sec from a tower 200 m high. The speed with which it strikes the ground is approximately 

1. 60 m/sec

2. 65 m/sec

3. 70 m/sec

4. 75 m/sec

A body freely falling from the rest has a velocity ‘v’ after it falls through a height ‘h’. The distance it has to fall down for its velocity to become double, is 

1. 2 h

2. 4 h

3. 6 h

4. 8 h

Velocity of a body on reaching the point from which it was projected upwards, is 

1. $v=0$

2. $v=2u$

3. $v=0.5u$

4. $v=-u$

A body projected vertically upwards with a velocity u returns to the starting point in 4 seconds. If g = 10m/sec², the value of u is  

1. 5 m/sec

2. 10 m/sec

3. 15 m/sec

4. 20 m/sec

Time taken by an object falling from rest to cover the height of h₁ and h₂ is respectively t₁ and t₂ . Then the ratio of t₁ to t₂ is 

1. h₁ : h₂

2. $\sqrt{h_1}:\sqrt{h_2}$

3. h₁ : 2h₂

4. 2h₁ : h₂