Front

When does a planet move most rapidly in its orbit?

Back

When it is nearest the Sun.

Front

What is the definition of 'weight'?

Back

The force in which gravity pulls on an object.

Front

What shape do the orbits of the planets take according to Kepler's first law?

Back

Ellipses.

Front

Which law explains why a cloud of gas particles in space collects into a sphere?

Back

Newton’s Law of gravity.

Front

What is the difference between mass and weight?

Back

Mass is how much matter is in an object, and weight is the gravitational pull on that object.

Front

What is gravity?

Back

A force that attracts two bodies towards each other.

Front

What is Newton's First Law of Motion?

Back

An object at rest stays at rest, and an object in motion stays in motion unless acted upon by a net external force.

Front

What is the formula for calculating weight?

Back

Weight = mass × gravitational acceleration (W = mg).

Front

What is the gravitational force between two objects dependent on?

Back

The masses of the objects and the distance between them.

Front

What is an ellipse?

Back

A geometric shape that is an elongated circle, which describes the orbits of planets.