Answer:
Frequency, 
Explanation:
We have,
Speed of radio waves is 
Wavelength of radio waves is 
It is required to find the frequency of the radio waves. The speed of a wave is given by :

So, the frequency of the radio wave is
.
Answer:

Explanation:
From the exercise we have that

<em><u>To find how far from the edge of the piano does the cat strike the floor, we need to calculate its time first </u></em>

At the end of the motion y=0m

Solving for t
or 
Since the <u>time</u> can't be negative the answer is t=0.73
Knowing that we can calculate how far does the cat strike the floor

KE = 1/2mv^2
KE= 1/2(2)(5)^2
KE= 25 J
Answer:
The last graph.
Explanation:
Gravitational potential energy is the energy possessed by a body at a given height from the Earth's surface.
The formula to find the gravitational potential energy is given as:

Where, 'U' is the gravitational potential energy.
'm' is the mass of the body.
'g' is the acceleration of the body due to gravity.
'h' is the height of the body above the Earth's surface.
So, from the above equation, it is clear that, gravitational potential energy is directly proportional to the height. So, as height increases, the gravitational potential energy increases. At the surface of Earth, where, height is 0, the gravitational potential energy is also zero.
Therefore, the correct graph is a straight line with positive slope and passing through the origin. So, the last option is the correct one.
Answer:
Phase Difference
Explanation:
When the sound waves have same wavelength, frequency and amplitude we just need the phase difference between them at a particular location to determine whether the waves are in constructive interference or destructive interference.
Interference is a phenomenon in which there is superposition of two coherent waves at a particular location in the medium of propagation.
When the waves are in constructive interference then we get a resultant wave of maximum amplitude and vice-versa in case of destructive interference.
- For constructive interference the waves must have either no phase difference or a phase difference of nλ, where n is any natural number.
- For destructive interference the waves must have a phase difference of n×0.5λ, where n is any odd number.