(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:
Given the final velocity (Vf) and the acceleration (a), the distance that should be traveled by the plane is calculated through the equation,
d = (Vf² - Vi²) / 2a
V1 should be zero because the light plane started the motion from rest. Substituting the given values,
d = ((33 m/s)² - 0)) / 2(3 m/s²)
The distance is therefore equal to 181.5 meters.
Weeds are very important agronomically because they reduce the yield of crops in three ways: by competing with the crop for water, light and nutrients, by interfering with crop harvest, and by contaminating harvested products with weed seeds and toxins. Weeds can reduce yield up to 50% and are responsible for millions of dollars in crop losses each year.
It’s biotic factor would be competition as Competition can be defined as an interaction between organisms or species, in which the fitness of one is lowered by the presence of another.
Initial volume of mercury is
V = 0.1 cm³
The temperature rise is 35 - 5 = 30 ⁰C = 30 ⁰K.
Because the coefficient of volume expansion is 1.8x10⁻⁴ 1/K, the change in volume of the mercury is
ΔV = (1.8x10⁻⁴ 1/K)*(30 ⁰K)(0.1 cm³) = 5.4x10⁻⁴ cm³
The cross sectional area of the tube is
A = 0.012 mm² = (0.012x10⁻² cm²).
Therefore the rise of mercury in the tube is
h = ΔV/A
= (5.4x10⁻⁴ cm³)/(0.012x10⁻² cm²)
= 4.5 cm
Answer: 4.5 cm
Answer:
D) wood rubbed against a rough surface feels hot
Explanation:
The heat is transferred from one form of energy (friction of the wood being rubbed against the surface) to another (heat energy).
