Unit 3 Test - Energy of Objects in Motion

TEST - 3/7/25

Energy

A measurement of an object's ability to do work.

Work

Applying a force in order to move an object in a given direction.

Joule

The unit of measurement for both energy and work.

Force

An influence that causes an object to undergo a change in speed, direction, or shape.

Positive Work

When an object moves in the same direction as the applied force, increasing the system's energy.

Negative Work

When an object moves in the opposite direction to the applied force, decreasing the system's energy.

Mechanical Energy

The energy of an object due to its motion and position, typically described in terms of kinetic and potential energy.

Kinetic Energy

The energy an object has due to its motion.

Potential Energy

The energy stored in an object due to its position or condition.

Gravitational Potential Energy

Potential energy due to the object's height above the ground.

Elastic Potential Energy

Potential energy stored in materials as a result of their stretching or compressing.

Conservation of Energy

The principle that energy cannot be created or destroyed, only transformed from one form to another.

Kinetic Energy Formula

KE = 1/2 mv^2, where m is mass and v is velocity.

Potential Energy Formula

PE = mgh, where m is mass, g is gravitational acceleration, and h is height.

Spring Constant

A measure of the stiffness of a spring, represented by k.

Elastic Potential Energy Formula

EPE = 1/2 kx^2, where k is the spring constant and x is the distance stretched or compressed.

Conservation of Energy Word Problem

If a roller coaster starts at a height of 50 meters and has a mass of 500 kg, what is its potential energy at the highest point? (Use the formula PE = mgh.)

Kinetic Energy Word Problem

A car with a mass of 1000 kg is traveling at a speed of 20 m/s. What is the car's kinetic energy? (Use the formula KE = 1/2 mv^2.)

Elastic Potential Energy Word Problem

A spring with a spring constant of 300 N/m is compressed by 0.2 meters. What is the elastic potential energy stored in the spring? (Use the formula EPE = 1/2 kx^2.)

Gravitational Potential Energy Word Problem

If a rock with a mass of 10 kg is lifted to a height of 10 meters, what is its gravitational potential energy? (Use the formula PE = mgh, where g = 9.8 m/s².)

Renewable Energy

Energy that is collected from resources that are naturally replenished, such as sunlight, wind, rain, tides, waves, and geothermal heat.

Non-Renewable Energy

Energy that comes from sources that will deplete or cannot be replenished, such as fossil fuels (coal, oil, natural gas) and nuclear energy.