Energy Practice Problems

A photon has a frequency (v) of 2.68 x 10⁶ Hz. Calculate its energy.

E = hv E = (6.63 x 10⁻³⁴ Js)(2.68 x 10⁶ Hz) E = 1.78 x 10⁻²⁷

Calculate the energy (E) and wavelength (λ) of a photon of light with a frequency (v) of 6.165 x 10¹⁴ Hz.

E = hv E = (6.63 x 10⁻³⁴ Js)(6.165 x 10¹⁴ Hz) E = 4.1 x 10⁻¹⁹ J λ = c/v λ = 3.0 x 10⁸/6.165 x 10¹⁴ λ = 0.487 x 10 ⁻⁶ λ = 4.87 x 10⁻⁷ m

A photon of light has a wavelength of 0.050 cm. Calculate its energy.

v = c/λ v = 3.0 x 10⁸/0.00050 v = 6.0 x 10¹¹ Hz E = hv E = (6.63 x 10⁻³⁴)(6.0 x 10¹¹ Hz) E = 3.978 x 10⁻²² J

Calculate the frequency and the energy of blue light that has a wavelength of 400 nm.

v = c/λ v = 3.0 x 10⁸/4.0 x 10⁻⁷ v = 7.5 x 10¹⁴ Hz 400 nm = 4.0 x 10⁻⁷ E = hv E = (6.63 x 10⁻³⁴)(7.5 x 10¹⁴) E = 4.97 x 10⁻¹⁹ J

Calculate the frequency of light that has a wavelength of 4.25 x 10⁻9 m. Identify the type of electromagnetic radiation.

v = c/λ v = 3.0 x 10⁸/4.25 x 10⁻⁹ v = 7.1 x 10¹⁶ Hz UV radiation

The wavelength of green light from a traffic signal is centered at 5.20 x 10⁻⁵ cm. Calculate the frequency.

v = c/λ v = 3.0 x 10⁸/5.2 x 10⁻⁷ v = 5.77 x 10¹⁴ Hz

Calculate the energy and frequency of red light having a wavelength of 6.80 x 10⁻⁵ cm.

v = c/λ v = 3.0 x 10⁸/6.80 x 10⁻⁶ v = 4.4 x 10¹⁴ E = hv E = (6.63 x 10⁻³⁴)(4.4 x 10¹²) E = 2.92 x 10⁻¹⁹ J

Calculate the wavelength and energy of light that has a frequency of 1.5 x 10¹⁵ Hz.

λ = c/v λ = 3.0 x 10⁸/1.5 x 10¹⁵ λ = 2.0 x 10⁻⁷ m E = hc/λ E = (6.63 x 10⁻³⁴)(3.0 x 10⁸)/2.0 x 10⁻⁷ E = 9.95 x 10⁻¹⁹ J