Physics 3 Final Exam 2011-2015 Everett Lipman 24. An experimental physicist rech
ID: 1479201 • Letter: P
Question
Physics 3 Final Exam 2011-2015 Everett Lipman 24. An experimental physicist recharges the car battery, and thestring theorist starts the car by turning the ignition on for 3.0 s. The total moment of inertia of the engine and flywheel is 0.70 kg-m2. As the car starts, the engine and flywheel are spun up to their idling rate of 1000 rpm (revolutions per minute). What is the rotational kinetic energy of the engine plus flywheel at 1000 rpm a. 230 J b. 460 J c. 920 d. 1900 J e. 3800 J With what efficiency energy of the engine and flywheel as the car energy is produced by the starter motor. is the energy delivered by the car battery converted to kinetic starts? Assume all of the rotational 25. a. 5.0% b. 15% C. 45% d. 64% e. 97%Explanation / Answer
21.
V = 10 V
I = 200 A
R = V/I
= 10/200
=0.05 ohm
Answer: a
22.
Confusing
23.
650 mAh = 200 A*t
650*10^-3 = 200*t
t=3.25*10^-3 hour
= 11.7 s
Answer: d
24.
I = 0.7 Kgm^2
w = 1000 rpm = 1000*2*pi / 60 rad/s = 104.72 rad/s
Kinetic energy = 0.5*I*w^2
= 0.5*0.7* (104.72)^2
= 3838 J
Answer: e
25.
I can't solve this