physics spring 2015. go over friction quest ◦ take the friction quest if missing yesterday ...
TRANSCRIPT
Go Over Friction Quest ◦ Take the Friction Quest if missing yesterday
Second Semester Review Assignment
Notes: Work
Review Mid-Semester Review◦ Collect Review
Notes: Work and Power
Practice: Work and Power
HW: Complete the Work and Power Assignment
Which of these would you classify as doing work?
◦ Lifting weights◦ Climbing stairs◦ Moving a couch◦ Trying to push a car that is stuck◦ Carrying you backpack around school
Work is the application of any force over a distance.
The equation for work is…Work = Force x distance
◦ If there is an applied force, but no movement is working being done?
How did we measure power in the circuits unit?
What did we say that the electricity company sells us actually?
Power is still the rate of energy used per time
In this unit:◦ Power = Work (J) / time (sec)◦ Units: Watts
A person expends 500J of energy while climbing a flight of stairs. If it takes this person 15 seconds to climb this flight, how much power did this person use?
If a car uses 100,000J of energy over the course of a 120 second drive. What is the power used?
If one horse can expend 30 Watts of power, how much horsepower was this car using?
Review Work Assignment
Horsepower Lab
Burning Calories Analysis and Conclusion of lab
HW: Complete Lab if not done in class
The energy of position or height
This tells us how much work an object could do.
GPE = mass * acceleration of gravity * height
Energy can never be created nor destroyed it just changes forms, from GPE to KE.
As GPE decreases, the amount of KE increases.
As KE decreases, the amount of GPE decreases.
Horsepower Lab
PE v. KE note review
Practice Problems: PE v. KE
Energy Skate Park
HW: PE v. KE assignment
How much potential energy does a ball have that is held motionless at a distance of 100m if the ball has a mass of 2kg.
Go Over exit slip procedures
Notes: Conservation of energy◦ Resubmit Exit slip from yesterday
Bowling Ball Demo◦ Chromebook research
Bowling Ball Explanation Activity
Energy is NEVER created or destroyed. It is only transformed into a different form of energy.
When an object is at rest above the ground contains 100% potential energy.
An object moving very close to the ground (height = 0m) it contains 100% KE
If a basketball is dropped from a height of 1m, how fast will it be moving when it hits the ground? The basketball has a mass of .3kg.
GPE (before dropped) = mgh = .3kg * 10m/s2 * 1m3 J
GPE at top = KE at bottom (Conservation of Energy)
KE (at bottom) = ½mv2 => ½ *.3kg * v2
v = .39 m/s
Review Bowling Ball Lab
Rollercoaster Problem◦ Conservation of Energy
Before tomorrow Quiz on LOCOE
HW: None, unless you need practice