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3 years ago

What is the velocity of all electromagnetic waves in a vacuum?

Physics

1 answer:

Nadya [2.5K]3 years ago

7 0

Answer:

$c=3\cdot 10^8 m/s$

Explanation:

All electromagnetic waves travel in a vacuum at the same speed, regardless of their frequency. The magnitude of their velocity is

$c=3\cdot 10^8 m/s$

This value is one of the universal constant and it is called speed of light.

According to Einstein's theory of special relativity, the value of c is the same for all inertial frames (it means that we measure always the same value of c in a vacuum, even if we are moving with respect to the light).

However, the speed of the electromagnetic waves decreases as they move through a medium. In particular, their speed decreases according to the equation:

$v=\frac{c}{n}$

where n is called index of refraction of the medium.

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Calculate the east component of a resultant 32.5 m/s, 35.0° east of north.

ValentinkaMS [17]

Answer:

East component is: 18.64 m/s

Explanation:

If the resultant is 32.5 m/s directed 35 degrees east of north, then we use the sin(35) projection to find the east component of the velocity:

East component = 32.5 m/s * sin(35) = 18.64 m/s

4 0

3 years ago

A car travels along a highway with a velocity of 24 m/s, west. The car exits the highway; and 4.0 s later, its instantaneous vel

zloy xaker [14]

Answer:

$4.25 m/s^{2}$

Explanation:

Change in velocity considering the x component will be

Final velocity-Initial velocity

$\triangle v_x= 16cos 45^{\circ}-24=-12.6862915 m/s$

Change in velocity considering the y component will be

Final velocity-Initial velocity

$\triangle v_y= 16sin 45^{\circ}-0=11.3137085 m/s$

Resultant change in velocity $=\sqrt {(-12.6862915 m/s)^{2}+(11.3137085 m/s)^{2}}=16.9982938 m/s$

Acceleration= change in velocity per unit time hence

$a= \frac {16.9982938}{4}=4.24957345\approx 4.25 m/s^{2}$

5 0

3 years ago

all objects near the earths surface-regardless of size and weight have the same force of gravity acting on them. is it true or f

pickupchik [31]

False: the force of gravity acting on different objects is different and depends on their mass

Explanation:

The answer is false.

The force of gravity acting on an object (also known as weight) near the Earth's surface is given by:

$F=mg$

where:

m is the mass of the object

$g=9.8 m/s^2$ is the acceleration of gravity

We see from the formula that the force of gravity acting on an object depends on the mass: the larger the mass of the object, the stronger the gravitational force acting on it, and the smaller the mass, the weaker the force of gravity.

The factor that does not change is the acceleration of gravity, which is constant ( $9.8 m/s^2$ ) if we are near the Earth's surface, and implies that all the objects in free fall accelerate at the same rate towards the ground, regardless of their size and weight.

Learn more about forces and weight here:

brainly.com/question/8459017

brainly.com/question/11292757

brainly.com/question/12978926

#LearnwithBrainly

5 0

3 years ago

Answers are ONLY allowed to be ionic, polar covalent, and nonpolar covalent.

Luba_88 [7]

A) It will be 2 covalent bonds
B) covalent bonds occur when there’s 2 atoms that share electrons. In this case by sharing the 2 pairs of valence electrons each atom has a total of 8 valence electrons

8 0

2 years ago

A meter stick balances horizontally on a knife-edge at the 51 cm mark. With two nickels stacked over the 6.0 cm mark, the stick

Oliga [24]

Answer:

65g

Explanation:

Two main conditions for equilibrium are:

I. The resultant force must be equal to zero. That is, sum of the forces acting in one direction about a point must be equal to the sum of the forces acting in the opposite direction about the same point.

II. The resultant moment must be equal to zero. That is, sum of the moments in one direction about a point must be equal to the sum of the moments in another direction about the same point.

For the above question,

the 51cm mark is the point where the resultant weight of the meter stick lies,

the pivot or point is the 45cm mark where the stick balanced when 2 nickels ( total mass (5.0g x 2) 10g were placed at the 6cm mark.

Using the conversion factor:

1000g(1kg) = 10N, we can convert mass to weight, calculate the weight of the meter stick then reconvert to mass.

That is,

mass of 2 nickels = 10g = 10/1000 = 0.01N.

Moment = Force x distance from line of force to pivot of rotation

Applying the principle of equilibrium,

Moment of left side = Moment of right side

0.01 x (45-6) = W x (51-45)

Where W = weight of the meter stick

W x 6 = 0.01 x 39

W x 6 = 0.39

W = 0.39/6

W= 0.065N

Therefore, mass of meter stick = 0.065 x 1000 = 65g.

4 0

3 years ago