Extra Credit #1 - Slide Challenge:
A child slides down a slide with a 34º incline, and at the bottom, her speed is precisely half what it would have been if the slide had been frictionless. Determine the coefficient of kinetic friction between the slide and the child.
Extra Credit # 2 - Ramp Challenge
A 7 kg block is given an initial velocity of 8.0 m/s going up an incline of 30 degrees. If the coefficient of friction between the block and the ramp is 0.3, what is the velocity of the block when it returns to the bottom of the ramp?
Extra Credit #3 - p.177 #80
Extra Credit #4 - summarize an article about COP 25, the Climate Conference in Madrid in December 2019.
A child slides down a slide with a 34º incline, and at the bottom, her speed is precisely half what it would have been if the slide had been frictionless. Determine the coefficient of kinetic friction between the slide and the child.
Extra Credit # 2 - Ramp Challenge
A 7 kg block is given an initial velocity of 8.0 m/s going up an incline of 30 degrees. If the coefficient of friction between the block and the ramp is 0.3, what is the velocity of the block when it returns to the bottom of the ramp?
Extra Credit #3 - p.177 #80
Extra Credit #4 - summarize an article about COP 25, the Climate Conference in Madrid in December 2019.
Extra Credit #4 - Read the Union of Concerned Scientists Article. Using the map, select 4 states with small MPG equivalents. Find out the power profile (the % of each power generation source in that state) using the EPA power profiler. Repeat for 4 states with large MPG equivalents.
Extra Credit #5 - Research Hydrogen Fuel Cell Vehicles with 2 goals:
1. what is the well-to-wheel process (in other words, how is hydrogen fuel made, stored and used?)
2. what is the well-to-wheel efficiency? 40% is shown. what did you find?
Extra Credit #6 - on PS 18 (about how Einstein's relativity equations helped finally explain Mercury's orbit)
Extra Credit #7 - banked curves. do #34 on p. 148. It's asking you come up with an expression for v that includes bank angle and coefficient of friction. Then find two values of bank angle and the corresponding coefficient of friction.
Extra Credit #8: do #1 and #4 from PS 25 using net force = ma. show that you obtain the same answer. Remember for #1 this is a 2-body problem.
In #4, you will need the coefficient of friction. You have enough information to find it, but I'm giving it to you: µk = 0.224
Extra Credit #9: Momentum
Momentum Challenge from PS 25 (3 pts on test):
Use the hyperphysics collisions link at goo.gl/foKrKO
to investigate the scenario in #4 further.
a) Using the same inputs, find the final velocity pairs that would result in the following:
b) Change the mass of cart B to determine:
c) Summarize in a table and discuss your findings briefly (2-3 sentences)
1. what is the well-to-wheel process (in other words, how is hydrogen fuel made, stored and used?)
2. what is the well-to-wheel efficiency? 40% is shown. what did you find?
Extra Credit #6 - on PS 18 (about how Einstein's relativity equations helped finally explain Mercury's orbit)
Extra Credit #7 - banked curves. do #34 on p. 148. It's asking you come up with an expression for v that includes bank angle and coefficient of friction. Then find two values of bank angle and the corresponding coefficient of friction.
Extra Credit #8: do #1 and #4 from PS 25 using net force = ma. show that you obtain the same answer. Remember for #1 this is a 2-body problem.
In #4, you will need the coefficient of friction. You have enough information to find it, but I'm giving it to you: µk = 0.224
Extra Credit #9: Momentum
Momentum Challenge from PS 25 (3 pts on test):
Use the hyperphysics collisions link at goo.gl/foKrKO
to investigate the scenario in #4 further.
a) Using the same inputs, find the final velocity pairs that would result in the following:
- Cart A stopping (you will have to enter a velocity value near zero, such as 0.0001 m/s)
- Cart A going the opposite direction that it went in #1
- Cart A and B colliding in a perfectly inelastic manner.
b) Change the mass of cart B to determine:
- what mass is necessary to stop car A
- what mass is necessary to make it reverse direction.
c) Summarize in a table and discuss your findings briefly (2-3 sentences)