Which of these events is an example of the doppler shift?
the amplitude of a wave on a string increases as the frequency decreases.
the amplitude of sound from a tuning fork decreases due to damping.
the frequency of light from a star increases as it moves toward us.
the intensity of an electromagnetic wave increases with the field strength.
the velocity of an electromagnetic wave changes as its medium changes.

Acylinder with a movable piston contains 11.7 moles of a monatomic ideal gas at a pressure of 1.32×10^5 pa. the gas is initially at a temperature of 300 k. an electric heater adds 43200 j of energy into the gas while the piston moves in such a way that the pressure remains constant. cp=20.79 j k^−1 mol^−1 for a monatomic ideal gas, and that the number of gas molecules is equal to avogadro's number (6.022×10^23) times the number of moles of the gas. (a) what is the temperature of the gas after the energy is added? (b) what is the change in volume of the gas? (c) how much work is done by the gas during this process?

The electronic structure or chlorine is 2.8.7 what is the electronic structure of fluorine?

A58-kg boy swings a baseball bat, which causes a 0.140-kg baseball to move toward third base with a velocity of 38.0 m/s.