Potential Energy
Potential Energy is _____ energy.
Potential Energy is STORED Energy
Definition of Kinetic Energy
Energy in MOTION.
The units for Energy.
Joules (J)
What is the potential energy of a 3 kg cell phone on Earth 2 meters above ground?
PE = mgh
3*9.8*2 = 58.8 J
Where did Brianna grow up?
What is the equation for Potential Energy? (Variables must be defined)
PE = mgh
Potential Energy = mass*gravity*height
What is the equation for Kinetic Energy? (Variables must be defined)
KE =1/2mv2
Kinetic Energy=1/2 mass*velocity2
The constant for gravity.
9.8 m/s
What is the Kinetic energy of a 75 kg person running on a track with a velocity of 3.5 m/s?
KE = 1/2mv2
1/2(75)*3.52 = 37.5*12.25
= 459.375 J
Where did Brianna attend high school?
An example of Potential Energy
Standing, Sleeping, on top of a peak on a roller coaster, etc.
Example of Kinetic Energy
Ball rolling, walking, ball bouncing, speed walking, hopping, etc.
The units for VELOCITY
Meters/second (m/s)
Atticus ran to the store 50 m away in 18 seconds. What is Atticus' velocity?
V = d/t
Velocity = distance / time
50/18=2.78m/s
What is Brianna's fiances name?
Collin
Julia had her 8 mg IPAD on her bed 2 m off the ground. What is the Potential Energy of the IPAD?
PE = mgh
PE=8*9.8*2
= 156.8 J
There is a roller coaster that is 625 kg moving at a velocity of 18.3 m/s. What is the Kinetic Energy?
KE = 1/2mv^2
KE = 1/2(625)(18.3)^2
312.5*334.89
= 104,653.125 J
What is the difference between speed and velocity?
Speed is how fast an object is going.
Velocity is the rate at which an object changes its position.
Calculate the velocity for a car traveling 700 m in 5 minutes.
V= d/t
700/5min*60sec
700/300=2.3 m/s
What is Brianna's dogs name?
Indy
Sophia is holding her phone on a flight of stairs at 8 m and has a Potential Energy of 42 J. What is the mass of the phone?
PE = mgh
42 = m*9.8*8
42 = 78.4*m
M = .54 kg
Loghan is on a 400 kg roller coaster with a velocity of 15 m/s. What is the Kinetic Energy of the roller coaster?
KE = 1/2mv2
1/2(400)152
45,000 J
*DOUBLE JEOPARDY*
Name a way energy can be lost
Friction or air resistance
A 4 kg ball is at the top of a hill 22 m high. The ball is then pushed down the hill at a speed of 4.6 m/s. Calculate BOTH the Potential and Kinetic Energy of the ball.
PE = mgh
PE = 4*9.8*22 = 862.4 J
KE = 1/2mv2
KE = 1/2(4)(4.6)2 = 42.32 J
Spell Brianna's last name
Mastrogiacomo