Answer:
4.6×10^-7 m or 0.46nm
Explanation:
From
Wo= hc/λ
Where:
Wo= work function of the metal
h= planks constant
c= speed of light
λ= wavelength
λ= hc/Wo
λ= 6.6×10^-34 × 3×10^8/4.30×10^-19
λ= 4.6×10^-7 m
Human error (average human reaction time is .2 seconds)
A bell or a siren or a ring in somewhere
The most exact answer is 78.4J also in this kind of options we can say answer "d"
