-- The acceleration of gravity is 9.8 m/s².
So if there's no air resistance, the speed of a falling object
always increases by 9.8 m/s for every second it falls.
Speed = (original speed) + (gravity x falling time)
-- If it has no vertical speed when it started, then at the end
of 3 seconds, its speed is
= (0) + (9.8 m/s² x 3 sec)
Velocity = 29.4 m/s downward .
The amount of solid does not affect how you are describing the solid so a is the answer
Current= voltage divided by resistance
120/30=4
Answer:
The maximum no. of electrons- 
Solution:
As per the question:
Maximum rate of transfer of charge, I = 1.0 C/s
Time, t = 1.0 h = 3600 s
Rate of transfer of charge is current, I
Also,

Q = ne
where
n = no. of electrons
Q = charge in coulomb
I = current
Thus
Q = It
Thus the charge flow in 1. 0 h:

Maximum number of electrons, n is given by:

where
e = charge on an electron = 
Thus

"physical science" is a branch of science that is based on practical tests and explanations of the different phenomena. It is based on scientific evidence and tests/experiments.
Some of the branches that are based on physical science are:
1- Astronomy
2- Electronics
3- Engineering
4- Radiology