5.1 - Intro to Energy and Work Flashcards
energy
Energy is the ability to do work.
We can ______ energy from one
object to another.
transfer
We can _______ energy inside an
object. The energy can even grow,
and we can use the energy at a later
time in the future.
store
We can ____ more energy or _____
more energy.
add; lose
work
the mechanical, actual, transfer of energy to or from a system by the pushes or pulls of external forces.
work (mechanical work) is when a force is ______ to an object, and the object is _______ in the SAME direction as the force (or at least a component of the
force).
applied; displaced
Work is the energy _______ to an object by an ________ force over some distance.
transferred; applied
true or false
work is a scalar quantity
true
work is measured in…
joules
is work being done here?
A person pushes a book across the floor
Yes. Force and Displacement are in the
same direction.
is work being done here?
A person holds a book for 2 minutes
No. Force but no displacement.
is work being done here?
A person holds a book and walks across the
room
No. Displacement but no
force applied to the book in
the direction of
displacement.
is work being done here?
A person drags the book with a string at an
angle of 60 degrees
Yes. Part of the force is in
the direction of the
displacement.
is work being done here?
A book is floating in space and drifting along
at 10 m/s
No. There is displacement
but no force.
positive work
Positive work – the displacement and force
are in the same direction
Ex: I push the book across the desk
