2. A lift in a shopping centre can transport 20 people to a height of 54 m in a time of 14 s. The lift compartment has a mass of 1420 kg and the average person has a mass of 60 kg. 10
a) Calculate the combined mass of the compartment and the 20 people in it.
b) Calculate the energy gained as the lift travels upwards.
Think about the lift as it rises. Which form of energy is increasing?
c) Calculate the rate at which energy is transferred by the lift motor to the compartment.

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?