Dropping Objects

Q.

A motor car moving with a uniform speed of $20m{s}^{-1}$ comes to rest on the application of brakes after travelling a distance of 10 m. Its acceleration is

1. 

2. 

3. 

4. 

Q.

An iron ball and a wooden ball of the same radius are released from the same height in vacuum. They take the same time to reach the ground. The reason for this is

1. There is no acceleration due to gravity in vacuum

2. Acceleration due to gravity in vacuum is same irrespective of the size and mass of the body

3. Acceleration due to gravity in vacuum depends upon the mass of the body

4. In vacuum there is a resistance offered to the motion of the body and this resistance depends upon the mass of the body

Q.

A stone dropped from the top of the tower touches the ground in 4 sec. The height of the tower is about

1. 20 m

2. 160 m

3. 40 m

4. 80 m

Q.

Two bodies of different masses $m_a$ and $m_b$ are dropped from two different heights a and b. The ratio of the time taken by the two to cover these distances are

1. a : b

2. b :a

3. 

4. 

Q.

A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00s after the front is dropped. The stones strike the water at the same time.

Which of these is the position time curve of the two stones as seen by a person who is standing directly below the point from where they are projected?

1. 

2. 

3. 

4. 

Q.

A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00 s after the front is dropped. The stones strike the water at the same time.

Which of these is the correct position-time curve of the stones w.r.t. the person who is throwing them?

1. 

2. 

3. 

4. 

Q. A stone is dropped from a certain height which can reach the ground in 5 second. If the stone is stopped after 3 second of its fall and then allowed to fall again, then the time taken by the stone to reach the ground for the remaining distance is

1. 3 sec
2. 2 sec
3. 4 sec
4. None of these

Q. Water drops fall at regular intervals from a tap which is above the ground. The third drop is leaving the tap at the instant the first drop touches the ground. How far above the ground is the second drop at that instant

1. 2.50 m
2. 3.75 m
3. 1.25 m
4. 4.00 m

Q.

A ball is dropped from a of height of 5m from ground. Find the velocity with which it hits the ground.

1. 5 m/s

2. 10 m/s

3. - 10 m/s

4. 

Q. A body is released from the top of a tower of height h. It takes $v=\frac{1}{2}b{t}^2+v_o$sec to reach the ground. Where will be the ball after time$\frac{t}{2}$sec.

1. At h/2 from the ground
2. At h/4 from the ground
3. Depends upon mass and volume of the body
4. At 3h/4 from the ground