Question

science study guide unit 3
name
★ as mass increases, the gravitational force between two objects ____________ (increases, decreases)
★ air resistance is a ____________ (contact force, non contact force)
★ gravity is a ____________ (contact force, non - contact force.)
★ as objects move away from each other, the gravitational force ____________ (increases, decreases.)
★ friction is a contact force acting on an object in the ____________ (opposite, same ) direction of the objects movement.
the force of gravity depends on

• how much mass the objects have
• how far apart they are

Explanation:

1. According to Newton's law of universal gravitation, gravitational force is directly proportional to the product of masses of two objects. So, as mass increases, gravitational force increases.
2. Air - resistance acts when an object is in contact with air molecules, so it is a contact force.
3. Gravity acts between objects without them having to be in physical contact, so it is a non - contact force.
4. Gravitational force is inversely proportional to the square of the distance between two objects. So, as objects move away from each other, the gravitational force decreases.
5. Friction opposes the relative motion of objects. So, it acts in the opposite direction of an object's movement.

Answer:

1. increases
2. contact force
3. non - contact force
4. decreases
5. Opposite