Conservation of energy and Collisions Notes
The conservation of energy is a very powerful law. It is easy to
use, mainly because it eliminates time and directions. But
because it eliminates time and d
Conservation of Energy Natural Law Notes
We can now define the concept of energy:
Energy is the capacity to do work (in ideal circumstances).
We all know that we can do work: exert a force through a
d
Exerting Force and Distance Notes
When you hold something, are you exerting a force on the
object? Yes.
When you hold something, are you doing work?
If you set the object on a table, does the table ex
Force and Power Notes
We know how force is related to energy, and how energy is
related to power. Can we relate power to force?
Work = F s , Power = DWork /Dtime =
F Ds /Dt (but Ds/Dt = v), so Power =
Contact Force and Energy Notes
Every force we have considered so far has an energy:
gravity (potential energy due to gravity)
friction (energy lost to heat)
spring (potential energy)
What about contac
Escape Speed fractions Notes
In the previous example, we threw something up that went about
32 meters high. How fast would we have to throw something to
make it escape from the earth altogether (if we
Forces and Energies Notes
Since Energy is the capacity to do work, and work is force thru a
distance, then we need to consider every force to see what kind
of energy is associated with it.
But from Ne
Potential Energy for spring Notes
PEspring = -sis Fspring ds where Fspring = -kx
Recall that the minus sign in the PE equation comes from the fact
that to store energy, we need to provide a force oppo
Kinetic Energy Notes
If we start with a single net force doing work on an object so that
the object picks up speed (and no other energy is involved), we
have:
Work = sisf F cos(q) ds .
Using Newtons S
Gravitational Potential Energy Notes
If we let the force of gravity act on an object as it moves, gravity is
exerting a force through a distance and may add or subtract
energy from the object. We can