Which of these is the best example of translation motion?

a.) coin spinning on a desk

b.) a ballerina standing on one foot

c.) a leaf blowing across the field

d.) a car in a parking lot with its engine running

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Positrons are spontaneously emitted from the nuclei of

Select for each of the following statements whether it is correct or incorrect. (a) in an isothermal expansion of an ideal gas. (b) the temperature remains constant. (b) the pressure remains constant. (c) there is work done by the gas. (d) there is heat added to the gas. (e) the change in internal energy equals zero.