Answer:
A) 443 Hz
B) She has to loosen the string
Explanation:
A) Given;
Beat frequency;f_beat = 3 Hz
Frequency of electronically generated tone; f_e = 440 Hz
We know that formula for beat frequency is given by;
f_beat = |f1 - f2|
Now, applying it to this question, we have;
f_beat = f_v - f_e
Where f_v is frequency of the note played by the violinist
Thus, plugging in the relevant values;
3 = f_v - 440
f_v = 3 + 440
f_v = 443 Hz
B) In the concept of wave travelling in a string, the frequency is directly proportional to the square root of the force acting on the string.
Now, for the violinist to get her violin perfectly tuned to concert A from what it was when she heard the 3-Hz beats, the beat frequency will have to be zero. Which means it has to decrease by 3 Hz. For it to decrease, it means that the force applied has to decrease as we have seen that frequency is directly proportional to the square root of the force acting on the string.
Thus, she would have to loosen the string.
Answer:
Newton's law of cooling says that the temperature of a body changes at a rate proportional to the difference between its temperature and that of the surrounding medium (the ambient temperature); dT/dt = -K(T - Tₐ) where T = the temperature of the body (°C), t = time (min), k = the proportionality constant (per minute),
Explanation:
A plane mirror forms a virtual image behind the mirror. The image is as far behind the mirror as the object is in front of it. A cannot see his image because the length of the mirror is too short on his side. However, he can see the objects placed at points P and Q, but cannot see the object placed at point R
Hope this helps Buddy!
~ Courtney
Answer: 22.5 km
Explanation: Solution:
v=d/t
Derive to find d
d= vt
= 45 km/h x 0.5 h
= 22.5 km
Cancel hours and the remaining unit is in km.
Answer:
The objects have the same altitude at the same time in the heights 22.4m and 36.6m.
Explanation:
The equation of the position
of the hot air balloon with respect to time is:

And the equation of the position
of the pellet with respect to time is:

As the altitude of the two objects must be equal, we can match these equations, so:

Solving this equation for t, we obtain:

Now, using the equation of the position of the balloon (we can use the other either, but the first one is easier) we can obtain the height of the places where the two objects have the same altitude at the same time:

In words, the hot air balloon and the pellet have the same altitude at the same time in the heights 22.4m and 36.6m.