What force governs the motion of our solar system?

A. Frictional Force
Incorrect. Friction is the resistance felt when one object is moved against another.

B. Gravitational Force
Correct! Gravity is the force that governs the motion of our solar system.

C. Electrical Force
Incorrect. Electrical force is the force of attraction or repulsion between two electrically charged bodies.

D. Magnetic Force
Incorrect. Magnetic force is the force exerted between magnetic poles, producing magnetization.

On what property or properties does the force of gravity between two objects depend?

A. The mass of the objects
Incorrect. The mass of the objects does affect the force of gravity but what else affects the force?

B. The distance between the objects
Incorrect. The distance between the objects does affect the force of gravity but what else affects the force?

C. The mass of the objects and the distance between the objects
Correct! Both the mass of the objects and the distance between them affect the force of gravity.

D.The mass and color of the objects
Incorrect. Although the mass of the objects does affect the force of gravity, color does not.

What is the general shape of the orbits that the planets take around the sun?

A. Circular
Incorrect. Although some planets appear to move in a circular path that is not quite right.

B. Rectangular
Incorrect. The planets do not move in a rectangular path.

C. Square
Incorrect. The planets do not move in a square shaped path.

D. Elliptical
Correct! The planets move in an elliptical path around the sun.

According to Issac Newton’s first law of motion, an object in motion tends to stay in motion unless acted upon by an outside force. What is the outside force that acts upon the planets and causes them to move in an elliptical orbit?

A. Inertia
Incorrect. Inertia is the resistance of a body to changes its momentum.

B. Gravity
Correct! The gravitational pull of the sun pulls the planets into orbit.

C. Magnetism
Incorrect. Magnetic force is the force exerted between magnetic poles, producing magnetization.

D. Friction
Incorrect. Friction is the resistance felt when one object is moved against another.