U11: Multiple Choice

Front

What is the formula for gravitational force between two objects?

Back

The gravitational force (F) between two objects is given by Newton's law of gravitation: F = G * (m1 * m2) / r^2, where G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between their centers.

Front

How does the mass of an object affect the gravitational force it experiences?

Back

The gravitational force experienced by an object is directly proportional to its mass. If the mass increases, the gravitational force also increases.

Front

What happens to gravitational force if the distance between two objects is halved?

Back

If the distance (r) between two objects is halved, the gravitational force increases by a factor of four, as F is inversely proportional to the square of the distance (F ∝ 1/r^2).

Front

What is the relationship between orbital radius and orbital period for satellites?

Back

The orbital period (T) of a satellite is related to its orbital radius (r) by Kepler's third law: T^2 ∝ r^3. This means that if the orbital radius increases, the orbital period also increases.

Front

Define 'free-fall' in the context of satellites.

Back

Free-fall occurs when an object is in a state of continuous free fall towards a planet or celestial body, resulting in the sensation of weightlessness. Satellites in orbit are in free-fall towards the planet but have enough tangential velocity to keep missing it.

Front

What is the significance of a satellite's mass in its orbit?

Back

A satellite's mass does not affect its orbital radius or period; it is the gravitational force and the initial velocity that determine these parameters.

Front

Explain the concept of gravitational field strength.

Back

Gravitational field strength (g) is defined as the force per unit mass experienced by a small test mass placed in the field. It is given by g = F/m, where F is the gravitational force and m is the mass of the test object.

Front

What is the effect of elevation on gravitational field strength?

Back

Gravitational field strength decreases with increasing elevation above the surface of a planet, as the distance from the center of the planet increases.

Front

What is the direction of acceleration for an object in circular motion?

Back

The direction of acceleration for an object in circular motion is always directed towards the center of the circle, which is also the center of the gravitational force acting on it.

Front

What is the relationship between the gravitational forces on two objects?

Back

According to Newton's third law, the gravitational force exerted by object A on object B is equal in magnitude and opposite in direction to the gravitational force exerted by object B on object A.