<span>step 1: energy required to heat coffee
E = m Cp dT
E = energy to heat coffee
m = mass coffee = 225 mL x (0.997 g / mL) = 224g
Cp = heat capacity of coffee = 4.184 J / gK
dT = change in temp of coffee = 62.0 - 25.0 C = 37.0 C
E = (224 g) x (4.184 J / gK) x (37.0 C) = 3.46x10^4 J
step2: find energy of a single photon of the radiation
E = hc / λ
E = energy of the photon
h = planck's constant = 6.626x10^-34 J s
c = speed of light = 3.00x10^8 m/s
λ = wavelength = 11.2 cm = 11.2 cm x (1m / 100 cm) = 0.112 m
E = (6.626x10^-34 J s) x (3.00x10^8 m/s) / (0.112 m) = 1.77x10^-16 J
step3: Number of photons
3.46x10^4 J x ( 1 photon / 1.77x10^-16 J) = 1.95x10^20 photons</span>
The missing part of the incomplete question is given below:
Which important step of scientific design is Shameka conducting?
repetition
replication
verification of results
using controlled variables
Answer:
Verification of results
Explanation:
The way toward gathering five examples of water from various sources is conveyed to confirm the outcome. By gathering water from five distinct areas of a similar source the analyst can genuinely find out the nature of the water in her region of remain.
On the off chance that after examples are tried it is found the water isn't sound, the outcomes would be acknowledged as it has been appropriately checked and a proper move would be made.
Thus, the correct answer is - verification of results
So the initial velocity is 15 m/s, the final velocity is 0 since it's at a complete stop and time is 10 seconds. Therefore:

Therefore, the acceleration is -1.5 m/s^2. The reason it's negative is due to the fact that the vector is going against it's original movement since it's decelerating.
Answer:
31.831 Hz.
Explanation:
<u>Given:</u>
The vertical displacement of a wave is given in generalized form as

<em>where</em>,
- A = amplitude of the displacement of the wave.
- k = wave number of the wave =

= wavelength of the wave.- x = horizontal displacement of the wave.
= angular frequency of the wave =
.- f = frequency of the wave.
- t = time at which the displacement is calculated.
On comparing the generalized equation with the given equation of the displacement of the wave, we get,

therefore,

It is the required frequency of the wave.
Answer:
8.97 Watt
Explanation:
Resistance, R = 20 ohm
Inductance, L = 10 mH
V(t) = 20 Cos (1000 t + 45°)
Compare with the standard equation
V(t) = Vo Cos(ωt + Ф)
Ф = 45°
ω = 1000 rad/s
Vo = 20 V
Inductive reactance, XL = ωL = 1000 x 0.01 = 10 ohm
impedance is Z.


Z = 22.36 ohm



Apparent power is given by
P = Vrms x Irms
P = 14.144 x 0.634
P = 8.97 Watt