One astronomer has observed an apparent lengthening of the electromagnetic waves given off by a star. which of these conclusions is correct about the star? its parallax is increasing. it is moving towards earth. its wavelength is decreasing. it is moving away from earth.

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.

Complete the sentence to describe the law of conservation of energy. the law of conservation of energy states that energy cannot be created or , but it can be

What is the coefficient of kinetic friction μk between the block and the tabletop?