Suppose you go outside and look at three stars. Star A is blue, star B is white, and star C is red. Which star is the hottest, and which star is the coldest?
(Figure 4)

a. Star A is the hottest, and star C is the coldest.
b. Star B is the hottest, and star C is the coldest.
c. Star A is the hottest, and star B is the coldest.

An insurance company wants to know if the average speed at which men drive cars is higher than that of women drivers. the company took a random sample of 27 cars driven by men on a highway and found the mean speed to be 72 miles per hour with a standard deviation of 2.2 miles per hour. another sample of 18 cars driven by women on the same highway gave a mean speed of 68 miles per hour with a standard deviation of 2.5 miles per hour. assume that the speeds at which all men and all women drive cars on this highway are both approximately normally distributed with unknown and unequal population standard deviations.

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Abicycle slows down when the rider applies the brakes. what type of energy transformation is involved in this example? a. kinetic energy into heat energy b. heat energy into potential energy c. potential energy into kinetic energy d. kinetic energy into mechanical energy