In a direct current, the electric charge, or current, only flows in one direction. In an alternating current, the electric charge changes periodically.
Water gets to the leaves in the tops of the tallest trees by something called the cohesion-tension theory. Water has two very unique properties called adhesion and cohesion. Cohesion is the tendency of water molecules to stick together with one another. The water sticks together, leaving no room for air, strengthening the "force" of the water going up the tree. The water also sticks to the sides of the xylem inside the tree. In addition to these properties, there are also the factors of negative and positive water potential. For more information, look up more details of the cohesion-tension theory.
Answer:
The correct answer is B-25 V
Explanation:
We apply Ohm's Law, according to which:
V = i x R
V = 5A x 5Ω
V= 25 V
Being V the potential difference whose unit is the VOLT, i the current intensity (Ampere) and R the electrical resistance (ohm)
Let <em>b</em> be the height of the building, and <em>y</em> the height of the ball at time <em>t</em>, given by
<em>y</em> = <em>b</em> - 1/2 <em>gt</em>²
where <em>g</em> = 9.8 m/s² is the magnitude of the acceleration due to gravity.
It takes the ball 8 s to reach the ground, at which point <em>y</em> = 0, so that
0 = <em>b</em> - 1/2 (9.8 m/s²) (8 s)²
<em>b</em> = 1/2 (9.8 m/s²) (8 s)²
<em>b</em> = 313.6 m
Answer:
100cm
Explanation:
Since the eyes are 6 cm below the top of her head, the point of incidence of the ray must be
200cm-3cm=197cm
Since the eyes are 194 cm from her feet, the point of incidence of this ray must be
194cm/2=97cm
So the lower edge of the mirror must be 97 cm from the ground and the vertical dimension of the mirror must be 197 cm - 97 cm = 100 cm, which is half the height of the person.