Energy Concepts
What is energy?
Ability to do work or cause change
What is kinetic energy?
Energy of motion
What is gravitational potential energy?
Stored energy due to height/position. The higher the object the more potential energy is stored.
What type of energy is made from vibrating molecules.
Thermal energy
Write the kinetic energy equation.
KE = ½mv²
What two things can cause an object’s energy to change?
Changes in motion (speed) or position (height)
How does increasing speed affect the total kinetic energy of an object.
The total kinetic energy increases.
How does decreasing height affect potential energy?
Potential energy decreases due to positioning.
Energy that is displayed as radio waves and x-rays.
Radiant energy
What does each variable represent in KE = ½mv²?.
m = mass, v = velocity
Where is potential energy greatest on a hill or ramp?
At the highest point.
Which has more kinetic energy: a car or bicycle moving at the same speed? Explain.
The car has more mass than the bike. While moving at the same speed.
Why is a chemical bond considered potential energy.
Because the energy is stored into the bonds. (stored energy is potential)
Energy produced when objects vibrate.
Sound energy
Calculate KE: mass = 2 kg, velocity = 5 m/s
25 J
Why does speed affect kinetic energy more than mass?
Because velocity is squared in the formula making speed a very important variable.
What happens to potential energy as an object falls and begins to gain speed?
It decreases the potential energy and turns into kinetic energy.
What types of energy are being used right now in the class room.
Electrical and sound(radiant/thermal )
Calculate PE: mass = 3 kg, height = 4 m (g = 9.8 m/s²)
117.6 J
Potential Energy is transferred to kinetic energy as the skater goes down the ramp.
Two objects have the same mass, but one moves twice as fast. Which has more KE?
The faster object will have the most kinetic energy.
What is stored mechanical energy and why is it important?
Stored mechanical energy is important because it is stored energy allowing us to move. Without it we wont be to move.
Track the energy changes in a flashlight from battery to light.
Chemical → electrical → radiant → thermal
A 2 kg ball is lifted 6 m. Calculate its potential energy.
117.6 J