Question

What is the wavelength of a 2500 kg truck traveling at a rate of 75km/h?

Answer 1

Given data

mass of truck (m) = 2500 Kg ,

speed of truck (v) = 75 Km/h ,

                             = 75 × (5/18) m/s  

                                 (since 1Km = 1000 meters and 1hr = 3600 seconds)

                             = 20.83 m/s

Determine the wavelength (λ) =?

We know that,

              wave length (λ) = h/mv

                         where, h = plank's constant, it is a physical constant

                                        = 6.626 × 10⁻³⁴ J-s

                                      m = mass of the object in kg

                                       v = velocity/speed of the object in m/s

     Now, substituting  all the values in the equation of wave length

                                       λ = 6.626 × 10⁻³⁴ /(2500 × 20.83)

                                          =  1.2723 × 10⁻³⁸ m

Wave length of the truck is  1.2723 × 10⁻³⁸ m

                               

Answer 2

m = mass of the truck traveling = 2500 kg

v = speed of the truck traveling = 75 km/h = 75 (km/h) (1000 m/ 1 km) (1 h /3600 sec) = 20.83 m/s

h = plank's constant = 6.63 x 10⁻³⁴

λ = wavelength of truck = ?

according to de broglie's principle, wavelength of truck is given as

λ = h/(mv)

inserting the values in the above equation

λ = (6.63 x 10⁻³⁴)/((2500) (20.83))

λ = 1.3 x 10⁻³⁸ m