Answer:
Figure A
Explanation:
At first, the inflated balloon is rubbed against the hair.
In this situation, the balloon is charged by friction: because of the friction between the surface of the balllon and the hair, electrons are transferred from the hair to the surface of the balloon.
As a result, when the balloon is detached from the hair, it will have an excess of negative charge (due to the acquired electrons).
Then, the balloon is placed in contact with the non-conducting wall.
The non-conducting wall is initially neutral (equal number of positive and negative charges).
Because the wall is made of a non-conducting material (=isolant), the charges cannot move easily through it. Therefore, even though the charges on the wall feel a force due to the presence of the electrons in the balloon, they will not redistribute along the wall.
Therefore, the charges on the wall will remain equally distributed, as shown in figure A.
Answer:
1 hour
Explanation:
Speed of the first boat = 30 mph
Speed of the second = 40 mph
The boats will cover different distances but the time taken will be the same.
Time taken by the boats = t
Distance = Speed × Time
Distance covered by the first boat = 30t
Distance covered by the second boat = 40t
Distance between the boats = 50 mi
From the Pythagoras theorem

Time taken by the boats when they are 50 mi away is 1 hour
<h2>
Answer: Toward the center of the circle.</h2>
This situation is characteristic of the uniform circular motion , in which the movement of a body describes a circumference of a given radius with constant speed.
However, in this movement the velocity has a constant magnitude, but its direction varies continuously.
Let's say
is the velocity vector, whose direction is perpendicular to the radius
of the trajectory, therefore
the acceleration
is directed toward the center of the circumference.
Given:
distance from the projector lens to the image, di
projector lens focal length, f
distance from the transparency to the projector lens, do
thin lens equation: 1/f = 1/di + 1/do
do = 4 inches
di = 8 feet
convert feet to inches, for uniformity.
1 foot = 12 inches
8 feet * 12 inches/ft = 96 inches
1/f = 1/96 inches + 1/4 inches
Adding fractions, denominator must be the same.
1/f = (1/96 * 1/1) + (1/4 * 24/24)
1/f = 1/96 + 24/96
1/f = 25/96
to find the value of f, do cross multiplication
1*96 = f * 25
96 = 25f
96/25 = f
3.84 = f
The focal length of the project lens is 3.84 inches
Answer:
The
electrons are moving through the superconductor per second.
Explanation:
Given :
Current
A
Charge of electron
C
Time
sec
From the formula of current,
Current is the number of charges flowing per unit time.

Where
number of charges means in our case number of electrons



Therefore,
electrons are moving through the superconductor per second.