Asample of blood is placed in a centrifuge of radius 16.0 cm. the mass of a red blood cell is 3.0 ✕ 10−16 kg, and the magnitude of the force acting on it as it settles out of the plasma is 4.0 ✕ 10−11 n. at how many revolutions per second should the centrifuge be operated?

Stion 13 of 20 : select the best answer for the question. 13. if a certain mass of mercury has a volume of 0.002 m3 at a temperature of 20°c, what will be the volume at 50°c? a. 0.002021624 m3 b. 0.004021624 m3 c. 0.000010812 m3 d. 0.002010812 m3

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.

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.