Astronomers believe that cosmic background radiation formed:

1 answer:

5 0

The assumption that the cosmic microwave background
is the remnant of the environment at the time of the big bang
or very shortly after it explains very well what we observe now.
So it is the current prevailing theory. "Believe" is not involved.

You might be interested in

What will be the ME of a machine that produces a 240 N work with a 300

Elden [556K]

Answer:

Efficiency = 80%

Explanation:

Given the following data;

Work output = 240 N

Work Input = 300 N

To find the mechanical efficiency of a machine;

$Efficiency = \frac {Out-put \; work}{In-put \; work} * 100$

Substituting into the equation, we have;

$Efficiency = \frac {240}{300} * 100$

$Efficiency = 0.8 * 100$

Efficiency = 80%

Therefore, the mechanical efficiency of the machine is 80 percent.

3 0

2 years ago

A 20.0-N weight slides down a rough inclined plane which makes an angle of 30 degree with the horizontal. The weight starts from

Ulleksa [173]

Answer:

$1270.64\ \text{J}$

Explanation:

m = Mass of object = $\dfrac{mg}{g}$

mg = Weight of object = 20 N

g = Acceleration due to gravity = $9.81\ \text{m/s}^2$

v = Final velocity = 15 m/s

u = Initial velocity = 0

d = Distance moved by the object = 150 m

$\theta$ = Angle of slope = $30^{\circ}$

f = Force of friction

fd = Work done against friction

The force balance of the system is

$\dfrac{1}{2}m(v^2-u^2)=(mg\sin\theta-f)d\\\Rightarrow \dfrac{1}{2}mv^2=mg\sin\theta d-fd\\\Rightarrow fd=mg\sin\theta d-\dfrac{1}{2}mv^2\\\Rightarrow fd=20\times \sin 30^{\circ}\times 150-\dfrac{1}{2}\times \dfrac{20}{9.81}\times 15^2\\\Rightarrow fd=1270.64\ \text{J}$