1
When does work occur?
When a force makes an object move in the direction of the force.
In a race car, kinetic energy transforms to ______________ energy due to friction
thermal
When a girl lifts a box onto a shelf, what type of energy increases?
gravitational potential energy
What happens to energy during every transformation and transfer?
Some energy transforms into thermal energy.
When pushing a bicycle that doesn't move, how much work is being done?
no work
What is a sign that energy transfer has occurred?
an object changes motion
sound changes
temperature changes
In what unit is energy measured?
Joules
______________________ is the sum of potential and kinetic energy in a system.
mechanical energy
What happens to potential energy as an object falls?
What happens to kinetic energy?
It decreases while kinetic energy increases.
What happens to a basketball's energy as it moves upward after being thrown?
Kinetic energy decreases while potential energy increases.
Which is true about energy transfer?
a. Energy transfer only occurs with moving objects
b. Energy transfer requires physical contact between objects
c. Energy transfer can occur through multiple forms
d. Energy transfer only happens in one direction
c. Energy transfer can occur through multiple forms
When a pendulum is at its highest point during its swing, it has maximum ______________ energy and minimum ________________ energy
potential
kinetic
At what point does a swinging pendulum have the most kinetic energy?
at its lowest point
____________________ is a force between two surfaces in contact with each other
friction
What happens to the total energy of a golf ball as it flies through the air?
it remains the same