Why do sound waves move faster through the ground than through the air?
a. particles of matter are packed more loosely in the ground than in the air.
b. particles of matter are packed more tightly in the ground than in the air.
c. air doesn’t contain any particles of matter to transmit sound waves.
d. the elevation of the ground is lower than the elevation of the air space.

A900 kg roller coaster car is travelling westward on the track and begins to slow down from 18m/s to 2m/s. how long does it take the roller coaster car to decelerate if the force acting on the car to slow it is 7024n? how far does the roller coaster travel during this time?

Two balls, each with a mass of 0.5 kg, collide on a pool table. is the law of conservation of momentum satisfied in the collision? explain why or why not

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?