Download 4 types of energy in physics: KE, PEg , PEs, Q

Reference Table Review
Mechanical Energy: Sum of all the Kinetic and Potential Energy 4 types of energy in physics: KE, PEg , PE s, Q
kinetic energy
gravitational
potential
energy
elastic
potential
energy
Internal
Energy
(heat)
only 3 of them figure into mechanical energy:
not part of mechanical energy
velocity = 4.0 m/s
2.0
kg
What is the Total Mechanical
Energy of the block at the instant shown
in this diagram
1.5 meters
h = 0
Total
Mechanical
Energy
Conservation
of
ENERGY
The total energy of a closed and isolated system remains constant
in equation form:
Conservation of Energy
vi = 0
This Anvil has
a gravitational potential
energy of 100 Joules
cliff
What is its kinetic
energy just as it reaches the ground?
h = 0
1. ID the system of objects and types of energy involved
2. set total sum of E's in one place = total sum of E's in another
3. expand and solve for unknown
98 N
50 m
Find.....
a) the work done lifting it up
b) the gravitational potential after lifting it up
c) the Kinetic energy it will have if it is dropped
and falls down 50 m (just before hit­ no air resist.)
A rock is thrown downward with an unknown
initial speed from a height of 5.0 m. Just prior to striking
the ground, the rock's speed
is 15 m/s. Ignoring air resistance,
use conservation of energy to determine the rock's initial speed.
5.0 m
cliff
1
4.0 m/s
m= 250 kg
3
35 m
h
Assuming the car is moving to the right at 4.0 m/s at
position 1, determine:
a) velocity at
position 2
2
9.0 m
No friction or air resistance.
a)
4
b) if the car is moving to the right at 12.4 m/s
at position 3, what is height, h?
c) How much kinetic
energy does the car
possess in position 4?
1
m= 250 kg
3
35 m
h
2
9.0 m
No friction or air resistance.
Assuming the car is moving to the right at 4.0 m/s at
position 1, determine
4
b) if the car is moving to the right at 12.4 m/s
at position 3, what is height, h?
1
m= 250 kg
3
35 m
h
Assuming the car is moving to the right at 4.0 m/s at
position 1, determine
2
9.0 m
No friction or air resistance.
c) How much kinetic
energy does the car
possess in position 4?
4