a). for velocity, you must have a number, a unit, and a direction.
Yes. This one isn't bad. The 'number' and the 'unit' are the speed.
b). the si units for velocity are miles per hour.
No. That's silly.
'miles' is not an SI unit, and 'miles per hour'
is only a speed, not a velocity.
c). the symbol for velocity is .
You can use any symbol you want for velocity, as long as
you make its meaning very clear, so that everybody knows
what symbol you're using for velocity.
But this choice-c is still wrong, because either it's incomplete,
or else it's using 'space' for velocity, which is a very poor symbol.
d). to calculate velocity, divide the displacement by time.
Yes, that's OK, but you have to remember that the displacement
has a direction, and so does the velocity.
Answer:
300 m/s
Explanation:
The difference in time between the two bangs is 1 s.
Thus;
t2 - t1 = 1
We know that distance/time = speed.
Thus;
d2/v - d1/v = 1
Multiply through by v to get;
d2 - d1 = v
Where v is speed of sound in air.
d1 = 350 m
d2 = (150 × 2) + 350 = 650 m
Thus;
v = d2 - d1 = 650 - 350 = 300 m/s
Gravity and air resistance
i took the test and got 100%
Answer:
If the radio wave is on an FM station, these are in Megahertz. A megahertz is one ... Typical radio wave frequencies are about 88~108 MHz .
Explanation:
To calculate the wavelength of a radio wave, you will be using the equation: Speed of a wave = wavelength X frequency.
Since radio waves are electromagnetic waves and travel at 2.997 X
10
8
meters/second, then you will need to know the frequency of the radio wave.
If the radio wave is on an FM station, these are in Megahertz. A megahertz is one million hertz. If the radio wave is from an AM radio station, these are in kilohertz (there are one thousand hertz in a kilohertz). Hertz are waves/second. Hertz is usually the label for the frequency of electromagnetic waves.
To conclude, to determine the wavelength of a radio wave, you take the speed and divide it by the frequency.
Typical radio wave frequencies are about
88
~
108
MHz
. The wavelength is thus typically about
3.41
×
10
9
~
2.78
×
10
9
nm
.
the answer is d they are essential to all ecosystems
