A car travels north for 20 km. The car then travels south for 35 km. If north is taken as the positive direction, what is the displacement of the car?

15 km

–55 km

55 km

–15 km

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is

The strong nuclear force acts over a small distance than the electrostatic force. true or false

7. see worksheet 1 for values of variables x1, x2 and x3 and answer the following questions: a. for each variable find the mean, median, coefficient of skewness, range and population standard deviation. b. compared to variable x1, how are the mean and median affected by extreme values (outliers) seen in x2 and x3. c. is the median or mean the better measure of location for x2 and x3? explain. d. explain the differences in the magnitudes of the skewness coefficients for the three variables. e. what is the relationship between the range and standard deviation looking across the three variables?