C.
Thanks me later, that's my answer.
Answer:
Un protón es aproximadamente 1835 veces más masivo que un electrón. Si está preguntando acerca de sus dimensiones físicas, nadie lo sabe. Los científicos actualmente no saben qué tan pequeños son los electrones. ¡Son más pequeños de lo que podemos medir actualmente y pueden no tener un tamaño en absoluto!
Explanation:
Answer:
f = pl / (l + p)
Explanation:
1/f = 1/p + 1/l
Find the common denominator of the right hand side.
1/f = l/(pl) + p/(pl)
Add:
1/f = (l + p) / (pl)
Take the inverse of both sides:
f = pl / (l + p)
I'll bite:
-- Since the sled's mass is 'm', its weight is 'mg'.
-- Since the coefficient of kinetic friction is μk, the force acting opposite to the direction it's sliding is (μk) times (mg) .
-- If the pulling force is constant 'F', then the horizontal forces on the sled
are 'F' forward and (μk · mg) backwards.
-- The net force on the sled is (F - μk·mg).
(I regret the visual appearance that's beginning to emerge,
but let's forge onward.)
-- The sled's horizontal acceleration is (net force) / (mass) = (F - μk·mg) / m.
This could be simplified, but let's not just yet.
-- Starting from rest, the sled moves a distance 's' during time 't'.
We know that s = 1/2 a t² , and we know what 'a' is. So we can write
s = (1/2 t²) (F - μk·mg) / m .
Now we have the distance, and the constant force.
The total work is (Force x distance), and the power is (Work / time).
Let's put it together and see how ugly it becomes. Maybe THEN
it can be simplified.
Work = (Force x distance) = F x (1/2 t²) (F - μk·mg) / m
Power = (Work / time) = <em>F (t/2) (F - μk·mg) / m </em>
Unless I can come up with something a lot simpler, that's the answer.
To simplify and beautify, make the partial fractions out of the
2nd parentheses:
<em> F (t/2) (F/m - μk·m)</em>
I think that's about as far as you can go. I tried some other presentations,
and didn't find anything that's much simpler.
Five points,ehhh ?
