To measure the height of the cloud cover at an airport, a worker shines a spotlight upward at an angle 75 from the horizontal. an observer 600 m away measures the angle of elevation to the spot of light to be 45. find the height h of the cloud cover.

Which of the following best describes internal energy? a. the difference between the kinetic and potential energies of the particles in a system b. the sum of the kinetic and potential energies of the particles in a system c. the sum of the kinetic and thermal energies of the particles in a system d. the difference between the kinetic and thermal energies of the particles in a system