Free Fall

Q.

If we drop three watermelons weighing $2kg$, $4kg$ and $6kg$ respectively from the same height and at the same time, which one of it will reach the ground first? (Given: negligible air resistance)

1. Watermelon weighing $4kg$

2. Watermelon weighing $2kg$

3. All three will reach at the same instant.

4. Watermelon weighing $6kg$

Q.

A body is dropped from a certain height at time $T=0$. It undergoes freefall and reaches the ground at time $T=t$ s. What is the expression for the height $h$ from which the body started its free fall?

Acceleration due to gravity is $g$.

1. $h=g{t}^2$

2. $h=gt$

3. $h=\left(\frac{1}{2}\right)g{t}^{-2}$

4. $h=\frac{1}{2}g{t}^2$

Q. The acceleration due to gravity at Earth's surface is directed towards the ________ of the Earth.

1. equator
2. south pole
3. centre
4. north pole

Q. A ball at rest is dropped from the top of a mountain. What is the distance travelled by the ball in the first two seconds? ( Take acceleration due to gravity $g=9.8m{s}^{-2}$)

1. $19.6m$
2. $39.2m$
3. $78.4m$
4. $101.4m$

Q.

A body is thrown up with an initial velocity of $10m{s}^{-1}$. It reaches a maximum height, $h$. Find the value of $h$. [Take acceleration due to gravity, $g=10m{s}^{-2}$]

1. $10m$

2. $15m$

3. $5m$

4. $20m$

Q.

A ball is thrown vertically upwards at speed of $20m{s}^{-1}$. Find the time taken by the ball to reach back to the original position. [Take acceleration die to gravity, $g=10m{s}^{-2}$]

1. $6s$

2. $4s$

3. $3s$

4. $10s$

Q. For the shown graph the slope of graph from point A to point B:

1. Continuously decreases
2. Continuously increases
3. First increases then decreases
4. First decreases then increases

Q. From the given graph which of the following can be concluded?

1. Displacement in increasing linearly from the beginning
2. Displacement increases linearly after certain time
3. Displacement remains constant throughout the process
4. None of the above

Q. The area of the shaded portion in the graph shown represents:

1. distance
2. speed
3. time
4. none of these

Q. The distance covered in the $n^{th}$ second is proportional to

1. $n^2$
2. $n$
3. $2n-1$
4. $2n^2-1$