Chuck drove 35mi from Austin to San Marcos in 40min, stopped 30min for a hamburger, and then drove 45mi to San Antonio in 50min. What was Chuck's average speed?

What is the measure of a change in an objects velocity?

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.

Atruck driver is attempting to deliver some furniture. first, he travels 8 km east, and then he turns around and travels 3 km west. finally, he turns again and travels 13 km to his destination. what is the drivers total displacement?