Answer:
I. They come from sources across space
II. They travel in a straight line from their source.
III. They can be reflected by some types of material.
Explanation:
Light wave can be defined as an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.
The following statements about light waves are true;
I. They come from sources across space.
II. They travel in a straight line from their source.
III. They can be reflected by some types of material. reflection occurs when a ray of light or wavefronts bounces off a smooth surface. Thus, when light hit a surface, it bounces back to the medium from which it was originally propagated with.
However, light waves cannot travel through all type of material except materials that are transparent or translucent but not opaque.
Answer and explanation;
In 1670 Gabriel Mouton, Vicar of St. Paul’s Church and an astronomer proposed the swing length of a pendulum with a frequency of one beat per second as the unit of length.
In 1791 the Commission of the French Academy of Sciences proposed the name meter to the unit of length. It would equal one tens-millionth of the distance from the North Pole to the equator along the meridian through Paris.It is realistically represented by the distance between two marks on an iron bar kept in Paris.
In 1889 the 1st General Conference on Weights and Measures define the meter as the distance between two lines on a standard bar that made of an alloy of 90%platinum with 10%iridium.
In 1960 the meter was redefined as 1650763.73 wavelengths of orange-red light, in a vacuum, produced by burning the element krypton (Kr-86).
In 1984 the Geneva Conference on Weights and Measures has defined the meter as the distance light travels, in a vacuum, in 1299792458⁄ seconds with time measured by a cesium-133 atomic clock which emits pulses of radiation at very rapid, regular intervals.
Decreasing pressure on a gas will cause its volume to increase, as it isn't being forced into a smaller space. Increasing temperature causes the atoms in the gas to contain more energy, making them move around more. This too increases the volume.
So basically both would increase the volume of the gas. Hope this helps
Rhyolitic <span>magma causes powerful and explosive volcanic eruptions
so its b</span>
Answer:
Vf = 4.40 m/s and θ = 88º
Explanation:
To solve this problem, let's look for the resultants of the force and with this we calculate the accelerations in each axis.
Let's use trigonometry to break down the forces
Sin 25 = F1x / F1
Cos 25 = F1y / F1
Fix = F1 sin 25
F1x = 1.85 sin 25
F1x = 0.78 N
F1y = 1.85 cos 25
F1y = 1.67 N
F2 = - 0.782 N j ^ (south)
F3 = - 0.750 N i ^ (west)
We write Newton's second law
X axis (East-West)
F1x - F3 = m ax
ax = (F1x - F3) / m
ax = (0.78 - (0.750)) / 0.325
ax = 0.092 m / s²
Y axis (North-South)
F1y - F2 = m ay
ay = (1.67- (0.782)) / 0.325
ay = 2.73 m / s²
Let's calculate the magnitude and direction of the acceleration
a = RA ax2 + ay2
a = RA 0.092² + 2.73²
a = 2.73m / s²
tan θ = ay / ax
θ = tan⁻¹ (2.73/0.092)
θ = tan⁻¹ 29.67
θ = 88º
We calculate the speed, notice that we use the total acceleration to be able to use the totol displacement
Vf² = vo² + 2 at D
Vf² = 0 + 2 2.73 3.55
Vf = √ 19.38
Vf = 4.40 m / s
θ = 88º