The ball took half of the total time ... 4 seconds ... to reach its highest
point, where it began to fall back down to the point of release.
At its highest point, its velocity changed from upward to downward.
At that instant, its velocity was zero.
The acceleration of gravity is 9.8 m/s². That means that an object that's
acted on only by gravity gains 9.8 m/s of downward speed every second.
-- If the object is falling downward, it moves 9.8 m/s faster every second.
-- If the object is tossed upward, it moves 9.8 m/s slower every second.
The ball took 4 seconds to lose all of its upward speed. So it must have
been thrown upward at (4 x 9.8 m/s) = 39.2 m/s .
(That's about 87.7 mph straight up. Somebody had an amazing pitching arm.)
Answer:

Explanation:
The electric field equation of a electromagnetic wave is given by:
(1)
- E(max) is the maximun value of E, it means the amplitude of the wave.
- k is the wave number
- ω is the angular frequency
We know that the wave length is λ = 700 nm and the peak electric field magnitude of 3.5 V/m, this value is correspond a E(max).
By definition:
And the relation between λ and f is:




The angular frequency equation is:


![\omega=2.69*10^{15} [rad/s]](https://tex.z-dn.net/?f=%5Comega%3D2.69%2A10%5E%7B15%7D%20%5Brad%2Fs%5D)
Therefore, the E equation, suing (1), will be:
(2)
For the magnetic field we have the next equation:
(3)
It is the same as E. Here we just need to find B(max).
We can use this equation:



Putting this in (3), finally we will have:
(4)
I hope it helps you!
Answer:
B. has a smaller frequency
C. travels at the same speed
Explanation:
The wording of the question is a bit confusing, it should be short/long for wavelength and low/high for frequency. I assume low wavelength mean short wavelength.
All sound wave travel with the same velocity(343m/s) so wavelength doesn't influence its speed at all. It won't be faster or slower, it will have the same speed.
Velocity is a product of wavelength and frequency. So, a long-wavelength sound wave should have a lower frequency.
The option should be:
A. travels slower -->false
B. has a smaller frequency -->true
C. travels at the same speed --->true
D. has a higher frequency --->false
E. travels faster has the same frequency --->false