In a day, an electrical resistance heater uses 10 kW-h of electricity. In the same day, the heater delivers 9 kW-h of heat to the house in which it is located. Is this possible or is this a perpetual motion machine? If so, what kind? Explain your reasoning.

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.

The ozone hole appears in antarctica during

Which of the following bonds would be most polar? a. c-i b. c-br c. c-cl d. c-f e. c-o