Formula for height
<span> r(t) = a/2 t² + v₀ t + r₀
</span><span> where
</span><span> a = acceleration = -32 ft/sec² (gravity)
</span><span> v₀ = initial velocity
</span><span> r₀ = initial height
</span><span> r(t) = -16t² + v₀ t + r₀
</span> <span>Tomato passes window (height = 450 ft) after 2 seconds:
</span><span> r(2) = 450
</span><span> -16(4) + v₀ (2) + r₀ = 450
</span><span> r₀ = 450 + 64 - 2v₀
</span><span> r₀ = 514 - 2v₀
</span><span> Tomato hits the ground (height = 0 ft) after 5 seconds:
</span><span> r(5) = 0
</span><span> -16(25) + v₀ (5) + r₀ = 0
</span> r<span>₀ = 16(25) - 5v₀
</span><span> r₀ = 400 - 5v₀
</span><span>
r₀ = 514 - 2v₀ and r₀ = 400 - 5v₀
</span> <span>514 - 2v₀ = 400 - 5v₀
</span><span> 5v₀ - 2v₀ = 400 - 514
</span> <span>3v₀ = −114
</span><span> v₀ = −38
</span><span> Initial velocity = −38 ft/sec (so tomato was thrown down)
</span><span> (initial height = 590 ft) </span>
The energy of a single photon is given by
where
is the Planck constant
f is the frequency of the wave (of the photon)
In our problem, the radio wave has a frequency of
, so if we put this value into the previous formula, we can find the energy of a single photon of this electromagnetic wave:
Answer: the first and last one
Explanation: hope i helped out :)
Answer:
633 nm
Explanation:
E = Energy difference = 1.96 eV
c = Speed of light = 3×10⁸ m/s
h = Planck's constant = 6.626×10⁻³⁴ J/s
Converting eV to J
1 eV = 1.6×10⁻¹⁹ J
1.96 eV = 1.96×1.6×10⁻¹⁹ Joule = 3.136×10⁻¹⁹ Joule
Photon energy equation
∴ Wavelength of light emitted by this laser is 633 nm