Explanation:
Electromagnetic waves are different from sound or water waves in such a way that water and sound waves are called mechanical waves that requires a material medium for their propagation.
Electromagnetic waves do no require a material medium for propagation.
- Electromagnetic waves are carried or transported by radiation and this can be passed through vacuums and different other materials.
- But mechanical waves such as water and sound waves requires a material medium for their propagation.
- They cannot pass through a vacuum.
Answer:
every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
Explanation:
Answer:
frequency = 1475.45 Hz
Explanation:
given data
frequency f1 = 1215 Hz,
frequency f2 = 1265 Hz
police car moving vp = 25.0 m/s
solution
speed of sound u = 343 m / s
speed of the other car = v
when the police car is stationary
the frequency the other car receives is
f2 = f1 ×
................1
and
the frequency the police car receives is
f2 = f1 ×
..................2
now from equation 1 and 2
![\frac{f2}{f1} = \dfrac{u+v}{u-v}](https://tex.z-dn.net/?f=%5Cfrac%7Bf2%7D%7Bf1%7D%20%3D%20%5Cdfrac%7Bu%2Bv%7D%7Bu-v%7D)
![\frac{1275}{1240} = \frac{u+v}{u-v}](https://tex.z-dn.net/?f=%5Cfrac%7B1275%7D%7B1240%7D%20%3D%20%5Cfrac%7Bu%2Bv%7D%7Bu-v%7D)
v = 4.77 m/s
and
frequency the other car receives is
f2 = f1 ×
......................3
and
the frequency the police car receives is
f2 = f1 ×
.......................4
now we get
f2 = f1 ×
f2 =
f2 = 1475.45 Hz
The auditory nerve carries an electrical signal to the brain, which turns it into a sound that we recognize and understand.
Answer:
No, because she is hoping that people will vote for her.
Explanation:
Altruism is when you do something for others and have very little expectation of getting something in return. In this case, Janetta expected something in return from her friends. We may not also be sure of the sincerity of Janetta appreciating friendship. From the above definition of altruism, we conclude that Janetta's actions are not altruistic because she hoped that people will vote for her.