When you see a tall, young, skinny man walking along the beach, you
observe that a tall, young, skinny man walked along the beach, and from
your observation, you know that a tall, young, skinny man walked along
the beach.
When you see a beach with nobody there, but there is a line of 5-toed
footprints in the sand along the beach, you infer that a human being
walked along the beach. If you are a skilled anthropologist, with some
talent and experience in a few other fields whose names escape me at
the moment, you might be able to make some careful measurements of
the length, width, depth, and shape of the footprints, and then you might
be able to infer that the person who walked along the beach was a tall,
young, skinny man. You would build all of your information from inference,
without any observations at all except for the line of footprints and your
measurements of them.
Answer:
Produces heat in various parts of machines.
Due to friction we have to exert more power in machines.
It opposes the motion.
Due to friction, noise is also produced in machines.
Due to friction, engines of automobiles consume more fuel which is a money loss.
Explanation:
Source: https://www.quora.com/What-are-the-disadvantages-of-friction

<u>Hydroelectric power,</u> also called hydropower is the electricity produced from generators driven by turbines that convert the potential energy of falling or fast-flowing water into mechanical energy.
<h2>
Answer:</h2>
(a) 6.95 x 10⁻⁸ C
(b) 6.25N/C
<h2>
Explanation:</h2>
The electric field (E) on a point charge, Q, is given by;
E = k x Q / r² ---------------(i)
Where;
k = constant = 8.99 x 10⁹ N m²/C²
r = distance of the charge from a reference point.
Given from the question;
E = 10000N/C
r = 0.250m
Substitute these values into equation(i) as follows;
10000 = 8.99 x 10⁹ x Q / (0.25)²
10000 = 8.99 x 10⁹ x Q / (0.0625)
10000 = 143.84 x 10⁹ x Q
Solve for Q;
Q = 10000/(143.84 x 10⁹)
Q = 0.00695 x 10⁻⁵C
Q = 6.95 x 10⁻⁸ C
The magnitude of the charge is 6.95 x 10⁻⁸ C
(b) To get how large the field (E) will be at r = 10.0m, substitute these values including Q = 6.95 x 10⁻⁸ C into equation (i) as follows;
E = k x Q / r²
E = 8.99 x 10⁹ x 6.95 x 10⁻⁸ / 10²
E = 8.99 x 10⁹ x 6.95 x 10⁻⁸ / 100
E = 6.25N/C
Therefore, at 10.0m, the electric field will be just 6.25N/C