Question

1. Find the velocity of an electron emitted by a metal whose threshold frequency is 2.18×10¹⁴ s−1 when it is exposed to visible light of wavelength 4.80×10⁻⁷ m .

2. Water is exposed to infrared radiation of wavelength 2.9×10⁻⁴ cm . Assume that all the radiation is absorbed and converted to heat. How many photons will be required to raise the temperature of 2.0 g of water by 2.2 K ?

3. Reset the PhET simulation (using the button in the lower right) and set it up in the following manner: select Oscillate, select No End, and use the parameters in parentheses by sliding the bars for Amplitude (1.00 cm), Frequency(1.20 Hz ), Damping (none), and Tension (highest). Using the available Rulers, calculate the frequency of a photon that corresponds to the wavelength of the resulting wave. Assume the length with units (cm) of the ruler represents the real photon wavelength and that the speed of light is 3.00×108 m/s.