If the book is not moving, which of the following statements must be true?

Bernie drove home from a vacation in 1.5 hours. he traveled a total distance of 60 miles. what was his average speed in miles per hour? a. 60 mph b. 90 mph c. 40 mph d. 55mph

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction

Acamcorder has a power rating of 20 watts. if the output voltage from its battery is 9 volts, what current does it use?