Answer:
Explanation:
Given data:
first case
Distance of electric field from center of sphere is r_1 <R
Electric field at r_1< R
second case
Distance of electric field from centre of sphere is r_1 < 2R
Electric field at r_1< 2R
so, we have
Answer:
created, destroyed, transforms
Explanation:
Energy cannot be created nor destroyed.
Energy is transformed from one form to another form.
- This is the postulate of the law of conservation of energy.
Energy is neither created nor destroyed simply implies that energy is not produce in any system. Nor is it destroyed.
What we have is energy transformation from one form to another.
I don't think that 4m has anything to do with the problem.
anyway. here.
A___________________B_______C
where A is the point that the train was released.
B is where the wheel started to stick
C is where it stopped
From A to B, v=2.5m/s, it takes 2s to go A to B so t=2
AB= v*t = 2.5 * 2 = 5m
The train comes to a stop 7.7 m from the point at which it was released so AC=7.7m
then BC= AC-AB = 7.7-5 = 2.7m
now consider BC
v^2=u^2+2as
where u is initial speed, in this case is 2.5m/s
v is final speed, train stop at C so final speed=0, so v=0
a is acceleration
s is displacement, which is BC=2.7m
substitute all the number into equation, we have
0^2 = 2.5^2 + 2*a*2.7
0 = 6.25 + 5.4a
a = -6.25/5.4 = -1.157
so acceleration is -1.157m/(s^2)
Answer: A
Explanation:
Proper Motion is the apparent angular motion of a star across the sky with respect to more distant stars. Typical proper motion is ~0.1 arcsec/year