A plucked guitar string produces a sound wave of frequency 0.44 kHz on a day when the speed of sound in 340 m/s. What is the wavelength of the sound wave?
0.33 m
0.44 m
0.55 m
0.66 m
0.77 m

The protons in a nucleus are approximately 2 ✕ 10^−15 m apart. consider the case where the protons are a distance d = 1.93 ✕ 10^−15 m apart. calculate the magnitude of the electric force (in n) between two protons at this distance.