Answer:
The answer is 0.83 seconds.
Explanation:
The formula of free fall is following:
Where g=9.8 m/s^2 and t=2 seconds, the rock takes:
19.6 meters. This is the half distance of the cliff. The whole distance is 39.2 meters. So it takes:
2.83 second to fall down completely. The rock takes the second half of the cliff in 0.83 seconds
Answer:
a. charge C experiences the greatest net force, and charge B receives the smallest net force
b. ratio=9
Explanation:
<u>Electrostatic Force</u>
Two point-charges and
separated a distance d will exert a force on each other of a magnitude given by the Coulomb's formula
Where k is the proportional constant of value
The diagram provided in the question shows four identical charges (let's assume their value is Q) separated by identical distance (of value d). The force between the charges next to others is
The force between charges separated 2d is
And the force between the charges A and D is
Now, let's analyze each charge and the force applied to them by the others
Let's recall equally signed charges repel each other and differently signed charges attrach each other
Charge A. It receives force to the left from B and C and to the right from D
Charge B. It receives force to the right from A and D and to the left from C
Charge C. It receives forces to the right from all charges.
Charge D. It receives forces to the left from all charges
Comparing the magnitudes of each force is just a matter of computing the fractions
a.
We can see the charge C experiences the greatest net force, and charge B receives the smallest net force
b.
The ratio of the greatest to the smallest net force is
The greatest force is 9 times the smallest net force