Paula finds that the temperature of a beaker of hot water drops several degrees in a few minutes. She says that there must be an exothermic reaction taking place in the water. do you agree? explain.

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

Within a pendulum, as potential energy decreases, energy increases. a. heat b. kinetic c. frictional d. gravitational

Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. the scale reads 830 n for the first 2.4 s after the elevator starts moving, then 930 n for the next 2.4 s. part a what is the elevator's speed 4.8 s after starting? express your answer with the appropriate units.