Answer:
The Universe became transparent to the light left over from the Big Bang when it was roughly 380,000 years old
Explanation:
<span>At an instant when the displacement is equal to a/2,
Potential energy U = 1/2ka(square) where a is displacement.
when a= a/2
U = 1/4ka(square)
U = E/4
Potential Energy = 1/4 Total energy</span>
Explanation:
Let
and 
The sum of the two vectors is


The difference between the two vectors can be written as


Answer:

Explanation:
We need only to apply the definition of acceleration, which is:

In our case the final velocity is
, the initial velocity is
since it departs from rest, the final time is
and the initial time we are considering is 
So for our values we have:

Answer:
53.13 °
Explanation:
In order to do this, we just need to apply the following:
tanα = Dy/Dx
Where:
Vy: speed of the ball in the y axis.
Vx: speed of the ball in the x axis.
At this point we do not need the speed of the first ball after the collision because in that moment is already heading in the direction that we are looking for. Therefore, we just need to use the innitial data to calculate the direction which the first ball will go.
According to this, then:
tanα = (40/30)
tanα = 1.3333
α = tan⁻¹(1.3333)
<h2>
α = 53.13°</h2>
This means that the final direction of the first ball is 53.13° and in the x axis because the starting momentum of this ball in the x axis has not dissapeared.
Hope this helps