Physics of Satellites and Gravity

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Questions and Answers

What is the primary characteristic of a geostationary satellite?

It orbits at a low altitude over the poles.
It changes its orbital position frequently.
It orbits in a highly elliptical path.
It appears to remain stationary above a specific point on Earth. (correct)

Which statement accurately describes polar satellites?

They have a higher orbital period than geostationary satellites.
They provide coverage only to one hemisphere.
They can potentially provide global coverage as the Earth rotates beneath them. (correct)
They orbit directly over the equator.

What does Kepler's first law state about the orbits of celestial bodies?

All planets have circular orbits.
The distance between a planet and the Sun is always the same.
Orbits of planets are ellipses with the Sun at one focus. (correct)
The speed of a planet's orbit is constant.

Which factor contributes to the experience of weightlessness for an object in orbit?

The object is in free fall towards Earth, matching orbital speed. (D) Signup and view all the answers

What is the relationship between the orbital period and the distance from the Earth for satellites according to Kepler's third law?

Period increases with distance according to the square of the distance. (C) Signup and view all the answers

What happens to the acceleration due to gravity as altitude increases?

It decreases. (A) Signup and view all the answers

How does the shape of the Earth affect the acceleration due to gravity?

It results in weaker gravity at the equator. (D) Signup and view all the answers

According to the formula for gravitational intensity, what does the 'r' represent?

Distance from the center of the massive object. (D) Signup and view all the answers

What effect does depth below the Earth's surface have on gravitational acceleration?

Gravitational acceleration decreases with increasing depth. (A) Signup and view all the answers

At the poles, the value of acceleration due to gravity is typically?

Higher compared to the equator. (C) Signup and view all the answers

What is the impact of Earth's rotation on gravitational acceleration?

Decreases gravity at the equator. (B) Signup and view all the answers

In gravitational potential energy, what does 'V' represent?

Gravitational potential. (C) Signup and view all the answers

Which of the following best describes the gravitational field of a uniform disc?

It varies with distance from the disc. (A) Signup and view all the answers

What formula represents the gravitational intensity due to a mass 'M' at distance 'r'?

$GmM/r^2$ (B) Signup and view all the answers

How does gravitational potential relate to gravitational field intensity?

Field intensity is the derivative of potential. (A) Signup and view all the answers

What shape describes the orbit of every planet around the Sun according to Kepler's first law?

Elliptical (D) Signup and view all the answers

Which law states that the line joining a planet to the Sun sweeps out equal areas in equal intervals of time?

Law of areas (D) Signup and view all the answers

According to the universal law of gravitation, the gravitational force is inversely proportional to which of the following?

The square of the distance between the particles (B) Signup and view all the answers

What does the formula $F_G = G \frac{m_1 m_2}{r^2}$ represent in physics?

Gravitational force (B) Signup and view all the answers

Which of the following characteristics is NOT true about gravitational force?

Dependent on the medium (A) Signup and view all the answers

What is the significance of Cavendish's experiment in relation to gravitation?

It determined the value of the gravitational constant, $G$. (C) Signup and view all the answers

Which of the following correctly describes the relationship in Kepler's third law?

$T^2 \propto R^3$ (A) Signup and view all the answers

What type of force is gravitational force classified as?

A conservative force (A) Signup and view all the answers

In the formula $F_G = G \frac{m_1 m_2}{r^2} \hat{r}$, what does $,\hat{r}$$ represent?

Unit vector from $m_1$ to $m_2$ (C) Signup and view all the answers

What does gravitational potential energy represent?

The work done in moving a body from infinity to a point in a gravitational field (A) Signup and view all the answers

Which equation correctly expresses the gravitational potential energy between two masses M and m?

$U = -rac{GMm}{r}$ (A) Signup and view all the answers

The dimensional formula for gravitational potential energy is?

$ML^2T^{-2}$ (D) Signup and view all the answers

What is the SI unit of gravitational potential energy?

Joule (J) (A) Signup and view all the answers

If the height of an object above the surface of the Earth is doubled, how is its gravitational potential energy affected?

It quadruples (D) Signup and view all the answers

For a body of mass m at height h, the formula for gravitational potential energy is?

$U = mgh$ (B) Signup and view all the answers

What factor does NOT affect gravitational potential energy between two masses?

Speed of the masses (C) Signup and view all the answers

In gravitational potential energy, which quantity is scalar?

Gravitational potential energy itself (D) Signup and view all the answers

How does increasing the mass of one of the bodies affect the gravitational potential energy?

It increases the potential energy (D) Signup and view all the answers

What happens to the gravitational potential energy as two masses approach each other?

It becomes more negative (D) Signup and view all the answers

Flashcards

Kepler's Law of Orbits

Planets orbit the Sun in ellipses, with the Sun at one focus.

Kepler's Law of Areas

A line from a planet to the Sun sweeps out equal areas during equal time intervals.

Kepler's Law of Periods

The square of a planet's orbital period is proportional to the cube of the semi-major axis of its orbit.

Universal Law of Gravitation

Every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between them.