# Equation of Motion of Free Fall

## Trending Questions

**Q.**When a ball is thrown vertically upwards, it goes through a distance of 19.6 m. Find the initial velocity of the ball and the time taken by it to rise to the highest point. (Acceleration due to gravity, g=9.8 ms−2) [3 MARKS]

**Q.**

The moons radius is $\frac{1}{4}$that of earth and its mass is$\frac{1}{80}$ times that of the earth. If g represents the acceleration due to gravity on the surface of the earth, that on the surface of the moon is

$\frac{g}{4}$

$\frac{g}{5}$

$\frac{g}{6}$

$\frac{g}{8}$

**Q.**

The initial velocity ${v}_{1}$ required to project a body vertically upward from the surface of the earth to just reach a height of $10R$, where$R$ is the radius of the earth, may be described in terms of escape velocity${v}_{e}$ such that ${v}_{i}=\sqrt{\left(\frac{x}{y}\right)}{v}_{e}$. The value of x will be_______.

**Q.**What will be the sign of accelertation due to gravity on a body near earth, when it is thrown vertically upwards? Take the upward direction as positive.

- Positive
- Negative
- Negligible
- Zero

**Q.**

A child is swinging a swing minimum and the maximum heights of swing from the Earths surface are $0.75mand2m$ respectively. What will be the maximum velocity of this swing?

**Q.**

If a ball is thrown vertically upwards with a velocity of 40ms, assuming (g=10ms2) then what will be the velocity of the ball after two seconds?

15 m/s

28 m/s

25 m/s

20 m/s

**Q.**

Calculate the value of $g$ on the surface of earth.

**Q.**

A stone piece is just dropped from a height of $180m$. If its velocity increases uniformly at the rate of $10m/{s}^{2}$, with what velocity will it strike the ground? How much time does the stone take to reach the ground?

**Q.**ntA body is projected vertically upwards with speed 10m/s and other at same time with same speed in downward direction from the top of a tower .The magnitude of acceleration of first body with respect to second is( g=10m/s)n

**Q.**The value of acceleration due to gravity at the surface of all planets is the same.

- True
- False

**Q.**

Name the factors on which the g of a planet depends.How?

**Q.**What will be the speed of a ball at it's maximum height when it is thrown vertically upwards with a speed of 9.8 m/s?

- Zero
- 9.8 ms−1
- 10 ms−1
- 1 ms−1

**Q.**

Calculate the acceleration due to gravity on the surface of the moon if the mass of the moon is $7.36\times {10}^{22}kg$and the radius is$1740km$. What will be the weight of a body of mass $10kg$ on the moon? Assume the value of $G$ $\left(G=6.67\times {10}^{-11}\frac{N{m}^{2}}{kg}\right)$.

**Q.**

Consider the following statements:

A. The acceleration due to gravity on the Moon is equal to that of the Earth.

B. The value of G is independent of the nature, size and mass of the interacting bodies.

Which of these statement(s) is/are correct?

- A only
- B only
- Both A and B
- Neither A nor B

**Q.**A ball falls off a table and reaches the ground in 1s. Assuming g=10ms−2. Calculate its speed on reaching the ground and the height of the table.

- 5ms−1 and 5m
- 20ms−1 and 10m
- 10ms−1 and 5m
- 30ms−1 and 15m

**Q.**

A heavy object and a lighter object are allowed to fall from the certain height in the absence of air then how acceleration and velocity varies?

**Q.**At what altitude (h) above the earths surface would the acceleration due to gravity be one fourth of its value at the earths surface

**Q.**The height which the acceleration due to gravity is reduced to one fourth of the gravity on the surface of the Earth is

**Q.**Acceleration due to gravity g near the surface of a planet of mass M and radius R is given by:

G is the Universal constant.

- g=GMR
- g=GRM2
- g=GM2R
- g=GMR2

**Q.**Pick out the correct relation(s) between universal gravitational constant (G) and acceleration due to gravity (g)

M = mass of earth,

R = radius of earth.

- g=GMR2
- g=R2GM
- G=gR2M
- G=MgR2

**Q.**What is the greatest height to which it will rise if a body is thrown vertically upward with a velocity of V

**Q.**What is free fall

**Q.**

A body weighs $1kg$on the surface of the Moon. If the mass of the Moon is $7.4\times {10}^{22}kg$, the radius of the Moon is $1740km$ and the gravitational constant is $6.7\times {10}^{-11}N{m}^{2}/k{g}^{2}$, calculate the acceleration produced in the Moon?

**Q.**

Name the acceleration produced in a body falling freely in a vacuum.

**Q.**A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate

(i) the maximum height to which it rises.

(ii) the total time it takes to return to the surface of the earth.

[5 Marks]

[Free fall]

**Q.**Consider two planets with equal masses having radius r1 and r2 such that r1>r2. The force of gravities at their surfaces are F1 and F2 respectively for a mass m. Which of the following conditions are true?

- F1>F2
- F1<F2
- F1=F2
- F1≤F2

**Q.**A ball thrown up vertically returns to the thrower after 6 s. Find the position of the ball after 4 s.

(Take acceleration due to gravity as 9.8 ms−2)

- 39.2 m
- 41.2 m
- 29.2 m
- 44.4 m

**Q.**A passenger in a moving train tosses a coin which falls behind him. It means that the motion of the train is

- Uniform
- Retarded
- Along circular tracks
- Accelerated

**Q.**

Derive the relationship between $g$‘ and ’$G$ .

**Q.**The acceleration due to gravity at three places A, B, and C on Earth are given by 9.8 m s−2, 9.81 m s−2 and 9.78 m s−2 respectively. Which of the following statements is true?

- B is the nearer to the centre of the Earth than the other two.
- All of the above.
- The order of the strength of the Earth's gravity is B>A>C.
- C is the farther from the centre of the Earth than the other two.