Newton’s Second LawPages 46-48

Describe your acceleration if you are in a circular motion. What is the net

force of your motion?

• You are constantly accelerating; the net force is equal to zero.

When an object moves is a circular motion, the net force on the object

is called centripetal force.

Explain how a satellite stays in orbit around the Earth.

• The Earth’s gravity pulls the satellite towards the Earth. The satellite’s speed (29,000 km/h or 18,000 mph) allows it to move fast enough to fall with a curve equal to the Earth’s curve.

• F-16 Plane = 1,500 mph• Bullet = 2,000 mph

What is air resistance?

• A form of friction.

The air resistance on an object depends on two things. What are

they?

1. The shape of the object.

1. The speed of the object.

What is the center of mass?

• Point in an object that moves as if all of the object’s mass were concentrated at that point.

Newton’s Second Law Equations:Acceleration = Net Force ÷ MassNet Force = Mass x AccelerationMass = Net Force ÷ Acceleration

Units of Measurement:Force NAcceleration m/s2

Mass kg

Page 48: Self Check, questions 2,4,5,6, and 7

2. The force of the Earth’s gravity will decrease so your weight will decrease.

4. The net force is pushing diagonally on the car and to the right.

5. When their forces are unbalanced.6. 1,500 kg × 2 m/s2 = 3,000 N7. 300 N ÷ 1,500 m/s2 = .2 kg