Following results are observed when sodium metal is irradiated with different wavelengths. Calculate (a) threshold wavelength and (b) Planck's constant.
`{:(lambda (nm),500,450,400),(v xx 10^(-5)(cm s^(-1)), 2.55 , 4.35, 5.20):}`

Explanation

To solve the problem step by step, we need to calculate the threshold wavelength (λ₀) and Planck's constant (h) using the provided data.

### Given Data:
- Wavelengths (λ) in nm: 500, 450, 400
- Velocities (v) in cm/s: 2.55 x 10^(-5), 4.35 x 10^(-5), 5.20 x 10^(-5)

### Step 1: Convert velocities from cm/s to m/s
To convert the velocities from cm/s to m/s, we divide by 100.
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