The correct choice is
D. 22 Hz and 42 Hz.
In fact, the beat frequency is given by the difference between the frequencies of the two waves:

In this problem, the beat frequency is
, therefore the only pair of frequencies that gives a difference equal to 20 Hz is
D. 22 Hz and 42 Hz.
Answer:
VAB = 20km/hr
Explanation:
<u>Given the following data;</u>
Velocity of car A, VA = 60km/hr
Velocity of car B, VB = 80km/hr
To find the relative velocity of B w.r.t A, VAB;
Since the two cars are moving in the same direction, we have;
VAB = VB - VA
Substituting into the equation, we have;
VAB = 80 - 60
<em>VAB = 20km/hr</em>
Therefore, the relative velocity of car B with respect to car A is 20 kilometers per hour.
Answer:
Every 2.2 kg is 1 pound. So mulitply 19 * 2.2. It's gonna be equal to 41.8
Explanation:
Answer:
2.36 x 10^6 J
Explanation:
Tc = 0°C = 273 K
TH = 22.5°C = 295.5 K
Qc = heat used to melt the ice
mass of ice, m = 85.7 Kg
Latent heat of fusion, L = 3.34 x 10^5 J/kg
Let Energy supplied is E which is equal to the work done
Qc = m x L = 85.7 x 3.34 x 10^5 = 286.24 x 10^5 J
Use the Carnot's equation


QH = 309.8 x 10^5 J
W = QH - Qc
W = (309.8 - 286.24) x 10^5
W = 23.56 x 10^5 J
W = 2.36 x 10^6 J
Thus, the energy supplied is 2.36 x 10^6 J.
Answer:
70 + 50 = 120 km/hr
Explanation:
The driver of either car would see the other car approaching or departing at 120 kph