6 - Unit 2, Section 2 - Day 1

Kinetic and Potential Energy

​Unit 2, Section 2

Multiple Choice

Which of the following is a metric system unit for energy?

• meter (m)

• joule (J)

• kilogram (kg)

• liter (L)

• Kinetic Energy – The energy an object has due to its motion

• Kinetic energy depends on:

  • The mass of an object

  • The velocity of an object

• A car may move more slowly than a baseball, but it has more kinetic energy because it has much more mass

Kinetic Energy

To calculate kinetic energy, we use:

• kilograms (kg) for mass

• meters per second (m/s) for velocity

Useful Units

The Formula for Kinetic Energy

A golf ball has a mass of 0.46 kg and is moving at a velocity of 80 m/s. What is the golf ball's kinetic energy?

Work-Together Problem

Multiple Choice

A cannonball with a mass of 5 kilograms is moving at a velocity of 250 m/s. What is the cannonball's kinetic energy?

• 156,250 J

• 625 J

• 50 J

• 1,250 J

Multiple Choice

Which has more kinetic energy: a 65-kilogram man running at 7.5 m/s, or a 65-kilogram man running at 10.5 m/s?

• A 65-kilogram man running at 7.5 m/s

• A 65-kilogram man running at 10.5 m/s

Multiple Choice

Which has more kinetic energy: a 150-kilogram go-kart moving at 50 m/s, or a 175-kilogram go-kart moving at 50 m/s?

• A 150-kilogram go-kart moving at 50 m/s

• A 175-kilogram go-kart moving at 50 m/s

Hotspot

At which point on this ride would the rollercoaster have the greatest kinetic energy?