Answer:
Frequency, f = 0.2 Hz
Explanation:
We have,
A baseball player throws 4 balls every 20 seconds.
It is required to find the frequency of the baseball.
Frequency of an object is defined as the number of times an event occurs. It is given by number of throws per unit time. It can be given by :

So, the frequency of his throw is 0.2 Hz.
Variables:
Source charge, Q = 3 micro C = 3 * 10^ - 6 C
E = electric field = 2.86 * 10 ^5 N/C
K = 8.99 * 10^9 N * m^2 / C
d = distance = ?
Formula:
E = K * Q / (d^2) => d^2 = K * Q / E
=> d^2 = 8.99 * 10^9 N * m^2 / C * 3 * 10^ -6 C / (2.86 * 10^ 5 N/C)
d^2 = 9.43 * 10 ^ -2 m^2
=> d = 3.07 * 10^-1 m
Answer: 0.307 m
Note: it is a long distance due to the Electric field is very low
I think the answer is Fossils formed gradually over time.
Where's the person that the question is talking about?