Answer:
Explanation:
a. The amplitude is the measure of the height of the wave from the midline to the top of the wave or the midline to the bottom of the wave (called crests). The midline then divides the whole height in half. Thus, the amplitude of this wave is 9.0 cm.
b. Wavelength is measured from the highest point of one wave to the highest point of the next wave (or from the lowest point of one wave to the lowest point of the next wave, since they are the same). The wavelength of this wave then is 20.0 cm. or 
c. The period, or T, of a wave is found in the equation
were f is the frequency of the wave. We were given the frequency, so we plug that in and solve for T:
so
and
T = .0200 seconds to the correct number of sig fig's (50.0 has 3 sig fig's in it)
d. The speed of the wave is found in the equation
and since we already have the frequency and we solved for the wavelength already, filling in:
and
v = 50.0(20.0) so
v = 1.00 × 10³ m/s
And there you go!
The correct answer is 1 and 4.
Burning of fossil fuels releases harmful gases to the atmosphere which leads to climate change. Burning of hydrogen gas releases water which has no negative effect on climate.
Burning of both fossil fuels and hydrogen takes place inside expensive fuel cells.
Fossil fuels are widely available and easy to locate whereas hydrogen is available in the combined form with other elements. Hydrogen are not found in pure form on earth.
Fossil fuels are non-renewable source of energy which means they cannot be replaced in short time.
Well we know it has to be greater than 300,000 km/s since we can't see it.
We can't calculate it any closer than that using the given information.
Answer: Constructive interference
Explanation: Just took the test
I think it is D. I hope this helps