Understanding Planetary Orbits and Kepler's Laws

What condition must be met for a satellite to maintain a perfect circular orbit?

• The satellite must be stationary relative to the Earth.

• The satellite must have a velocity greater than the escape velocity.

• The satellite must have the right velocity with gravity acting as a centripetal force.

• The satellite must have zero velocity.

What happens to the shape of an orbit if a planet's velocity is slightly larger or smaller than required for a circular orbit?

• The orbit becomes a perfect circle.

• The orbit becomes a straight line.

• The orbit remains unchanged.

• The orbit becomes an ellipse.

What is the eccentricity of a circular orbit?

• 0

• 1

• Greater than 1

• Between 0 and 1

According to Kepler's First Law, where is the Sun located in a planet's elliptical orbit?

• At the center of the ellipse

• At one of the foci of the ellipse

• Outside the ellipse

• At the midpoint of the major axis

Why is the common belief that seasons are caused by Earth's elliptical orbit incorrect?

• Because Earth's orbit is a perfect circle.

• Because Earth's orbit is highly eccentric.

• Because the tilt of Earth's axis causes seasons.

• Because the Sun is at the center of Earth's orbit.

What does Kepler's Second Law imply about the speed of a planet in its orbit?

• The speed is faster when the planet is closer to the Sun.

• The speed is constant throughout the orbit.

• The speed is independent of the planet's position in the orbit.

• The speed is slower when the planet is closer to the Sun.

What does Kepler's Second Law state about the areas swept by a line joining a planet and the Sun?

• The areas are proportional to the planet's mass.

• The areas are equal in equal time intervals.

• The areas are unequal in equal time intervals.

• The areas depend on the planet's distance from the Sun.

According to Kepler's Third Law, how does the distance of a planet from the Sun relate to its orbital period?

• The farther the planet, the longer the period.

• The farther the planet, the shorter the period.

• The closer the planet, the longer the period.

• The distance does not affect the period.

What is the key insight provided by Kepler's Third Law?

• The time period of a planet's orbit is independent of its distance from the Sun.

• Planets move faster when closer to the Sun.

• Planets have elliptical orbits with the Sun at the center.

• The time period of a planet's orbit increases with distance from the Sun.

In what scenario do Kepler's and Newton's laws become insufficient for predicting orbits?

• When dealing with objects in circular orbits.

• When dealing with objects in elliptical orbits.

• When dealing with very massive objects like black holes.

• When dealing with very small objects.