15. a heat engine operating between temperatures of 100 k and 500 k has an efficiency of 55%. if each cycle expels 800 j of heat, what is the change in entropy of the universe due to each cycle? a) 5.33 j/k b) 5.09 j/k c) 4.80 j/k d) 4.44 j/k e) 0.00 j/k

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?