9. Given the setup of the experiment, derive an expression for the coefficient of kinetic friction using the energy model of an isolated system. Be sure to specify what object(s) make up your
system and show all work algebraically.
di
d2

In which situation is the acceleration of a car negative? question 5 options: a)the velocity of a car was 75 km/hr over 4 hours. b)the velocity of a car reduced from 50 km/hr over one minute. c)the velocity of a car increased from 40 km.h to 75 km/h over 15 minutes. d)the velocity of a car was 45 km/hr at 2: 00pm and at 4: 00pm its velocity was 85 km/ht.