What is the recommended amount of time that a teenager should be participating in physical activity a: 30 min b: 60 min c: 45 min d: 15 min

Astone is thrown into a pond. what happens to the amplitude of the resulting waves as they get farther from the point where the stone hit the water? explain.

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?

Select all the correct answers. which three statements about electromagnetic radiation are true?