The answer is 5.88 · 10⁻⁷<span> m.</span>
To calculate this we will use the light equation:
v = λ · f,
where:
v - the speed of light (units: m/s)
<span>λ - the wavelength of the ray (units: m)
</span>f - the frequency of the ray (units: Hz = 1/s <span>since Hz means cycles per second (f=1/T))
</span>
It is given:
f = 5.10 · 10¹⁴ Hz = 5.10 · 10¹⁴<span> 1/s
v = 2.998 </span>· 10⁸<span> m/s
</span><span>λ = ?
</span>
If v = λ · f, then λ = v ÷ f:
λ = 2.998 · 10⁸ m/s ÷ 5.10 · 10¹⁴ 1/s
= 0.588 · 10⁸⁻¹⁴ · m
= 0.588 · 10⁻⁶ m
= 5.88 · 10⁻⁷ m
I believe the answer is 3 Newtons!
If the two cups are the same/equal in all regards the spoon makes the difference in heat loss. Metal spoon is a good conductor, heat conducts up the spoon handle. Radiant and convection losses occur in the surrounding air. Metal becomes a “heat sink”.
Spoon will feel warmer to the touch than a pottery or foam cup that is not a good conductor.
E kin = 1/2 • m • v^2
E kin: kinetic energy
m: mass
v: velocity
