Answer:5000000000hertz
Explanation:
Wavelength=6cm=6/100 m=0.06m
Frequency=velocity/wavelength
Frequency=(3×10^8)÷0.06
Frequency=5000000000 hertz
Answer:
F=248.5W N
Explanation:
Newton's 2nd Law tells us that F=ma. We will use their averages always. The average acceleration the tennis ball experimented is, by definition:

Since we start counting at 0s and the ball departs from rest, this is just 
So we can write:

Where in the last step we have just multiplied and divided by g, the acceleration of gravity. This allows us to introduce the weight of the ball W since W=gm, so we have:

Substituting our values:

Where the average force exerted has been written it terms of the tennis ball's weight W.
The direction of a vector multiplied by a scalar is only affected if the scalar is negative, in which case the vector will now be in the opposite direction. If the scalar is positive, the vector will only change in magnitude
Answer:
The velocity of the tennis ball is 4.52 m/s.
Explanation:
Given that,
The distance covered by ball, d = 9.5 meters (due south)
Time, t = 2.1 sec
Let v is the velocity of the tennis ball. We know that the velocity of an object is given by the total distance covered divided by total time taken. It is given by :

So, the velocity of the tennis ball is 4.52 m/s. Hence, this is the required solution.
Kinetic energy is energy of motion.
In the cases of a stretched rubber band, water in a reservoir, natural gas, or an object suspended above the ground, everything is just laying there, and nothing is moving. There's nothing there that has kinetic energy.
If there's any wind, then air is moving. The moving air has kinetic energy.