Transcript PS-6 Test Review - Purdyphysicalscience

PS-6 Test Review
What must increase to effect the KE
of an object the most?
The velocity because it is squared
in the formula… KE= ½ mv2
A car transfers chemical potential
energy to _______ energy.
Mechanical energy
What effects the GPE of an object?
 Gravity,
mass,
& height
What is the SI Unit for energy
 Joule (J)
 According to the law of conservation
of energy, energy in the universe
cannot be created or destroyed,
therefore it is _________.
 transferred
 How much work is done when a 10N
force is applied over a 3 meter
distance?
 W = f x d = 10N x 3m = 30 J
 For an object to have KE, it must
be________________.
 moving
Where does a pendulum have:




Maximum KE?
Maximum PE?
Increasing KE?
Increasing PE?
What are the requirements to do
work?
 An object must move
 The motion of the object must be
in the same direction as the
applied force on the object
You rub a balloon against your
sweater:
 What charge does the balloon have and why?
 Negative – it picked up electrons
from your sweater
 What charge does the sweater have and why?
 Positive – it has less electrons after
transferring some to the sweater
 By what method was charge transferred?
 friction
What is the difference?
 Charge by conduction
 Charging an object by contact
 Charge by induction
 Charging an object by holding a
charged object near it
 Which of the above is lightning and
why?
 Charge by induction…the clouds and
the ground don’t touch each other
What is static electricity?
 The accumulation of excess
electric charges on an object
 Static meaning no motion
Electroscope
 What does it detect?
 An unknown electric charge
 When the leaves spread apart what
has happened?
 The charges are the same and repel
 How does it detect an unknown
charge?
 leaves come together if the charges
are different (attract)and will spread
apart if like charges (repel)
Electric Current
 What is it?
 The flow of electrons through a conductor
 How is it measured?
 Amperes (A)
 ______ is the force or push for electrons in a
circuit and is measured in ______.
 Voltage, Volts (V)
 ______ is electrical friction and is measured in
_________.
 Resistance, Ohms ()
Ohm’s Law
 What is it?
 The current in a circuit = voltage
divided by the resistance
 What is the current in a circuit with a
6 volt battery and 2 ohms of
resistance?
 I = V/R = 6V / 2  = 3 A
Electric Circuits
 A _______circuit has one path for electrons
to flow.
 Series
 A _______ circuit has more than one path
for electrons to flow.
 Parallel
Series Circuit
 What happens if a bulb is removed?
 All the lights go out – open circuit




If you add a bulb what happens to:
Voltage - increases
Current - decreases
Resistance - increases
Parallel Circuit
 What happens if a bulb is removed?
 The other bulbs stay lit & are brighter
 If a path is added, what happens to:
 Voltage – Stays the same
 Current - Increases w/ each path
 Resistance – decreases w/ each path
 Resistance in a circuit is effected by
what 3 things?
 Large diameter – less resistance
 Long wires – greater resistance
 Increase in temperature – increase
resistance
Electromagnet
 What is it?
 Electricity runs through a wire and
causes a magnetic field
 What can be done to increase it’s
strength?
 Coil more wire around the object
 In electromagnetic induction, electric
current is produced when a loop of
wire is moved through a
___________.
 Magnetic field
What is the difference between AC
and DC current?
 AC =current moves back and
forth
 DC = flows in one direction
 A generator converts _______ energy
to ________ energy.
 Mechanical / Electrical
 An electric motor converts
__________ energy to ________
energy.
 Electrical / Mechanical