A100 kg mass is pulled along a frictionless surface by a horizontal force f such that its acceleration is 8.0 m/s2. a 20 kg mass slides along the top of the 100 kg mass and has an acceleration of 3.0 m/s2. (it thus slides backward relative to the 100 kg mass.) (a) what is the frictional force exerted by the 100 kg mass on the 20 kg mass? (b) what is the net force acting on the 100 kg mass?

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?