A coin is placed in an empty beaker. When a transparent liquid is poured into the beaker, the apparent depth of the coin is found to be 40% less than the real depth. What is the refractive index of the liquid? The options for the answer are 0.4 / 0.6 / 1.2 / 1.7

Explain how plate tectonics have changed earth’s surface over time. include the role of plate tectonics in the creation of landforms.

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.

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.