Explain how water freezing and thawing causes weathering and the type of weathering it would be considered.

Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.

A1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km. what is the magnitude of the friction force required to keep the car from sliding?