Answer:
2.3 × 10⁻²⁰ N, attractive
Explanation:
An electron has a negative charge and a proton has a positive charge. Opposite charges attract each other. We can calculate the magnitude of this attractive force (F) using Coulomb's law.
where,
k: Coulomb's constant
q: charges
r: distance
The modulus of the force is 2.3 × 10⁻²⁰ N.
If there wasn't any battery before, then there was no current
in the circuit before, and there IS one now. That's just about
the greatest change possible.
If there WAS a battery there before and you added another one
in series with it, then there are a few different possibilities for the
effect on the current in the circuit:
-- If the new battery has the same voltage as the original one,
AND you connect the new one so that they're both in the same
direction, then the current in the circuit will become double the
original current (twice as much as it was before).
-- If the new battery has the same voltage as the original one, AND
you connect the new one so that they're in opposite directions, then
the two batteries cancel each other, the total voltage becomes zero,
and the current in the circuit completely disappears.
-- If the voltage of the two batteries is different AND you connect
the new one so that they're both in the same direction, then the
current in the circuit increases, by a factor of
(sum of the two battery voltages)
divided by
(voltage of the original battery alone).
-- If the voltage of the two batteries is different AND you
connect the new one so that they're in opposite directions,
then the current in the circuit decreases, by a factor of
(difference of the two battery voltages)
divided by
(voltage of the original battery alone)
and the current flows in the direction of whichever battery has
the greater voltage. If the new battery has greater voltage than
the original one alone, then the current reverses, and flows in
the opposite direction.
I think that covers all the possibilities.
Answer:
1. increases
2. increases
3. increases
Explanation:
Part 1:
First of all, since the box remains at rest, the horizontal net force acting on the box must equal zero:
F1 - fs = 0.
And this friction force fs is:
fs = Nμs,
where μs is the static coefficient of friction, and N is the normal force.
Originally, the normal force N is equal to mg, where m is the mass of the box, and g is the constant of gravity. Now, there is an additional force F2 acting downward on the box, which means it increases the normal force, since the normal force by Newton's third law, is the force due to the surface acting on the box upward:
N = mg + F2.
So, F2 is increasing, that means fs is increasing too.
Part 2:
As explained in the part 1, N = mg + F2. F2 is increasing, so the normal force is thus increasing.
Part 3:
In part 1 and part 2, we know that fs = Nμs, and since the normal force N is increasing, the maximum possible static friction force fs, max is also increasing.
Answer:
The slope of the graph is what you need. That tells you the speed not the velocity. In order to find the velocity you would also need to know the direction of the motion.
