define mechanical energy. using the example of the skateboarder on the half-pipe, explain how kinetic and potential energy relate to the mechanical energy at different positions.

Which of the following explains why it took so long for the public to accept the negative health effects of smoking? a)people were waiting for counter reasons, and those were presented. b)scientists had not completely finalized their results, which took 30 years. c)cigarettes were cheaply available and media channels were very inefficient. d)cigarette manufacturers were trying hard to bring an alternative into the market

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final