## Module Question 35

$\lambda=\frac{h}{p}$

Isabel Day 1D
Posts: 48
Joined: Fri Aug 09, 2019 12:15 am

### Module Question 35

Question 35 on the module says:

Calculate the wavelength of a 275 kg single-seat electric car traveling at a speed of 125 km.hr-1. Do electric cars have wavelike properties?

I've done this problem many times and keep getting the wrong answer. I always get 1.57x10^-39. What am I doing wrong? This isn't even one of the answer choices.

VLi_2B
Posts: 99
Joined: Sat Sep 14, 2019 12:15 am

### Re: Module Question 35

First use the De Broglie equation:
λ = h/mv, where λ is wavelength, h is Planck's constant, m is the mass of a particle (g), moving at a velocity v (m/s)

Change and check units
125km/hr = 34.72m/s

λ = (6.6261 x 10^-34 m^2 kg/s)/ (275kg x 34.72m/s)
λ = 6.94 x 10-38 m