Exam 2

Question 1

5.4 Start

Energy is…….

Answer 1

the capacity to do work

Chemical
Thermal
Electrical
Light
Mechanical - Elastic and Potential

Question 2

Kinetic Energy

Answer 2

• the energy that a body has because it is moving
• “energy of motion”

K = 1/2mv^2
J or Joules

Question 3

GRAVITATIONAL
POTENTIAL ENERGY

Answer 3

• the energy that a body has because of its
  position, relative to earth’s surface
• “potential for motion”

PE = - mgh
J or Joules

Question 4

STRAIN POTENTIAL ENERGY

Answer 4

• the energy a body has because it has
  been deformed and has a tendency
  to return to its original position.
• “potential to return to original shape”

SE = 1/2kx^2
J or Joules

k how far you stretched out that material

k is the stiffness of the material. It is a given constant.

Question 5

CONSERVATION
OF ENERGY

Answer 5

• the total mechanical
  energy remains
  constant if gravity is the
  only external force

Question 6

Energy - Capacity to do
work =

Answer 6

Work done
by the body
is EQUAL to
the CHANGE
IN ENERGY of
body

Question 7

Start of Friction

Friction is a

Answer 7

contact force
- resist sliding
- more

Question 8

Friction Two Factors

Answer 8

1. Nature of the surfaces (u) mu
2. force holding surfaces together