Work and Energy Flashcards
Which term has a different SI Unit than the rest?
Force
What is the ability to do work?
Energy
Work is done on an object…
whenever a force causes displacement to an object
energy that is due to the motion of an object is…
kinetic energy
when is no work done?
when a barbell is held overhead
energy stored in the gravitational field of interacting bodies is
gravitational potential energy
How does the kinetic energy of an object change if the object’s speed doubles?
The kinetic energy increases by a factor of 4
Friction does -400 J of net work on a moving car. How does this affect the kinetic energy of the car?
The kinetic energy decreases by 400 J.
The work-kinetic energy theorem states that
The net work done on an object equals the change in the kinetic energy of the object.
Mechanical energy is not conserved when
friction is present within the system.
The mechanical energy of a system of objects is
the sum of kinetic energy and all relevant forms of potential energy.
Which of the following is true of the conservation of energy in a closed system?
Mechanical energy is always conserved.
Which requires more work: lifting a 10 kg load a vertical distance of 2 m, or lifting a 5 kg load a vertical distance of 4 m?
They require the same work
