<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>
Answer:
90-100meters
Explanation:
The overall length limitation of a UTP cable is 90-100meters. Once this limitation is reached, a repeater is employed to transfer data.
Answer:
Explanation:
given,
frequency of tuba.f = 64 Hz
Speed of train approaching, v = 8.50 m/s
beat frequency = ?
using Doppler's effect formula
v_s is the velocity of the source
v is the speed of sound, v = 340 m/s
now,
f' = 65.64 Hz
now, beat frequency is equal to
hence, beat frequency is equal to 1.64 Hz
Work=f.d
Work=100*50 = 500
Power = work/time = 500/4
=125 watt
Answer:
<span>5010J</span>
Explanation:
Work is force times distance, or
<span>W=F⋅d</span>.
Substitute in values from the question to get
<span>W=8.35⋅<span>102</span>N⋅6m=50.1⋅<span>102</span>Nm=5010<span>J</span></span>
