(a) We can find the current flowing between the walls by using Ohm's law:

where

is the potential difference and

is the resistance. Substituting these values, we get

(b) The total charge flowing between the walls is the product between the current and the time interval:

The problem says

, so the total charge is

The current consists of Na+ ions, each of them having a charge of

. To find the number of ions flowing, we can simply divide the total charge by the charge of a single ion:
T² caries directly as R³ .
This is Kepler's 3rd law of planetary motion .
Answer:
Explanation:
There will be loss of potential energy due to loss of height and gain of kinetic energy .
loss of height = R - R cos 14 , R is radius of hemisphere .
R ( 1 - cos 12 )
= 13 ( 1 - .978 )
h = .286 m
loss of potential energy
= mgh
= m x 9.8 x .286
= 2.8 m
gain of kinetic energy
1/2 m v ² = mgh
v² = 2 g h
v² = 2 x 9.8 x 2.8
v = 7.40 m /s
Answer: 10.3m/s
Explanation:
In theory and for a constant velocity the physics expression states that:
Eq(1): distance = velocity times time <=> d = v*t for v=constant.
If we solve Eq (1) for the velocity (v) we obtain:
Eq(2): velocity = distance divided by time <=> v = d/t
Substituting the known values for t=15s and d=155m we get:
v = 155 / 15 <=> v = 10.3