Potential Energy
What two factors affect potential energy?
Answer: Mass and height
What two factors affect kinetic energy?
Mass and speed
What type of energy transformation happens when you turn on a light bulb?
Electrical → Light + Thermal
When is a roller coaster’s potential energy the greatest?
At the top of the first hill
Heat always transfers from what to what?
From hot to cold
If you double the mass of an object, what happens to its potential energy?
It doubles
Which factor affects kinetic energy more—mass or speed?
Speed, because it’s squared in the formula KE = 1⁄2mv2
Lighting a match is an example of what energy transformation?
Chemical → Light + Thermal
When is a roller coaster’s kinetic energy the greatest?
At the bottom of the hill
How does conduction transfer heat?
Through direct contact between particles
Why does potential energy increase when an object is raised higher?
Because gravitational potential energy depends on height above the ground
What happens to kinetic energy if you double the speed?
It quadruples
What type of energy transformation happens in a battery-operated toy?
Chemical → Electrical → Mechanical
What happens to total mechanical energy (PE + KE) as a pendulum swings?
It stays constant (ignoring friction)
How does convection transfer heat?
Through circulation moving in currents (heat rises, cold sinks). Usually in fluids or gases.
A 2 kg rock is lifted from 2 m to 4 m. How does its potential energy change?
It doubles
Describe the relationship between kinetic energy and speed on a graph.
Nonlinear (curved upward—exponential)
What type of energy transformation happens in a solar panel?
Radiant (Light) → Electrical
Where does a basketball have the least potential energy?
When it’s on the ground
How does radiation transfer heat?
Through electromagnetic waves—no medium needed
Describe the relationship between potential energy and height on a graph.
It’s a positive linear relationship (PE increases as height increases)
Compare the shapes of the KE vs. mass and PE vs. mass graphs.
Both increase linearly, but KE also depends heavily on speed
Explain why no energy is “lost” during transformations.
Energy is conserved; it changes form but total energy remains constant
Describe what happens to a pendulum’s PE and KE as it swings.
PE is highest at the top, KE highest at the bottom; they constantly transform into each other
Give an example investigation for each type of heat transfer.
Conduction: metal spoon in hot water; Convection: boiling water; Radiation: feeling the sun’s warmth