# de Broglie Wavelength of a Rifle Bullet

A certain rifle bullet has a mass of 8.13 g. Calculate the de Broglie wavelength of the bullet traveling at 1721 miles per hour. Physical constants are found below:

Physical Constants

Quantity Symbol Value

speed of light in a vacuum c 2.99792458Ãƒ-108 m/s (exact)

Planck's constant h 6.6260755Ãƒ-10-34 JÂ·s

universal gas constant R 0.082057 LÂ·atm/(molÂ·K)

8.3145 J/(molÂ·K)

8.3145 m3Â·Pa/(molÂ·K)

8.3145 LÂ·kPa/(molÂ·K)

0.083145 LÂ·bar/(molÂ·K)

62.364 LÂ·Torr/(molÂ·K)

the Avogadro constant NA 6.02214179Ãƒ-1023 formula units/mol

mass of an electron me 9.109382Ãƒ-10-28 g

5.4858Ãƒ-10-4 amu

mass of a proton mp 1.67262171Ãƒ-10?24 g

1.007276466 amu

mass of a neutron mn 1.67492729Ãƒ-10?24 g

1.008664915 amu

charge on an electron e -1.602176487Ãƒ-10-19 C

Boltzmann constant k 1.3806503Ãƒ-10-23 J/K

Faraday constant F 96485 C/mol of electrons

Rydberg constant RH 1.096776Ãƒ-107 m-1

2.178688Ãƒ-10-18 J

3.288052Ãƒ-1015 s-1

de Broglie wavelength equation is lamda = h/mu

HINT:

Miles per hour is not the SI unit for velocity. Below are some useful relationships to obtain the velocity of the bullet in correct SI units.

(1.609 km)/(1 mile) (1 mile)/(3600 s) (?10?^3 m)/(1 km)

https://brainmass.com/chemistry/stoichiometry/de-broglie-wavelength-rifle-bullet-504045

## SOLUTION This solution is **FREE** courtesy of BrainMass!

First convert speed to SI unit.

v = 1721 mph = 1721 miles / hours = 1721* 1.609km / 1 mile * 1 mile / 3600s * 1000m / 1km

The mass of the bullet is m = 8.13g = 8.13*10^-3 kg

The de Broglie wavelength is calculated

lambda = h / mv = 6.6260755*10^-34 J*s / (8.13*10^-3 kg)*(769.2 m/s) = 1.06*10^-34 m

https://brainmass.com/chemistry/stoichiometry/de-broglie-wavelength-rifle-bullet-504045