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3 years ago

What connects space and time in our Universe?

Physics

1 answer:

Bumek [7]3 years ago

4 0

Answer:

Einstein had realized in 1905, that space and time, are intimately connected with each other. ... Thus one can think of space and time together, as a four-dimensional entity, called space-time. Each point of space-time is labeled by four numbers, that specify its position in space, and in time.

Explanation:

You might be interested in

When we jump on a concrete surface the feet are more seriously hurt than while jumping on a sand

ohaa [14]

In this situation when using newton's third law, the floor is very rigid and thus when we fall the floor applies the same amount of force on us with which we were falling on it. The rigidness of the concrete floor makes it difficult for it to absorb some of our force. On the other hand sand is not rigid on impact sine it changes its shape while it absorbs a large amount of our falling force and a small fraction of this force is applied on is. That is why we don't get hurt

4 0

4 years ago

A weight of 6 kg increases the speed of its force from 2 m / s to 4 m / s. By how many joules does the kinetic energy of the bod

Leviafan [203]

Answer:

36 J

Explanation:

Let's start off with the Kinetic Energy formula: 1/2m $v^{2}$

So to find the change in Kinetic Energy, you would first have to find the Kinetic Energy in the beginning and in the end.

*Note: Mass: you incorrectly wrote weight = 6 kg- because weight is a force you have to write 6 Newtons. If you are talking about the mass, you would write 6 kg. If you are talking about weight, you would write 6 Newtons. The difference will make significant changes to the answer, so I will give you the answer for both.

If 6 kg is the MASS:

Beginning: find the kinetic energy.

Plug in all parts of the formula: 1/2mv^2 = $\frac{1}{2}$ (6)(2 squared)= $\frac{1}{2}$ (6)(4)= 12 J

End: find the kinetic energy.

Plug in all parts of the formula: 1/2mv^2= $\frac{1}{2}$ (6)(4 squared)= $\frac{1}{2}$ (6)(16)= 48 J

Answer:

36 J

If 6 kg is the WEIGHT:

We know that the weight formula is mg, or mass times acceleration due to gravity (which is always 9.8 m/s^2). Plug in the numbers:

Weight = mass x acceleration due to gravity

6 = mass x 9.8

6 = 9.8m

*Divide both sides*

mass = 0.6 kg

Now, we can use the mass to find the kinetic energy.

Beginning: find the Kinetic Energy

Plug in all parts of the formula: 1/2mv^2 = $\frac{1}{2}$ (0.6)(2 squared)= $\frac{1}{2}$ (0.6)(4)= 1.2 J

End: find the Kinetic Energy

Plug in all parts of the formula: 1/2mv^2= $\frac{1}{2}$ (0.6)(4 squared)= $\frac{1}{2}$ (0.6)(16)= 4.8 J

Answer:

3.6 J

(this answer is not very feasible, so 36 J is the way to go. But just remember, don't mix up weight and mass again- as you can see, they lead to different answers!)

4 0

3 years ago

Astronomers classify stars according to their (1 point) distance from Earth. color, size, and absolute brightness. age and paral

charle [14.2K]

Answer:

All of the above

Explanation:

Astronomers use all of those measures to classify stars. If you want to look more into classifying stars, check out the Hertzsprung-Russel Diagram. It covers how to identify red giants, main sequence, dwarf stars, ect. Distance from earth is typically measured in light years. The color of stars generally determines how hot they are. (Blue stars are the hottest) Also, the parallax method is used to measure stars that are closer to earth. This method relies heavily on geometry though.

Hope this helped!

8 0

3 years ago

3. Write the numbers given below in scientific notation.

KIM [24]

Answer:
a) 3 * 10^9 ms
b) 1.6 * 10^-9 gm
c) 6.4 * 10^6 m
d) 5.48 * 10^5 s
Explanation:
Scientific notation is always written in [number from 0-10] (multiplied by) [10] raised to the power 'n'

4 0

2 years ago

A tennis ball hits with an initial velocity of 25 m/s [10 o above the

Sav [38]

First, calculate the components of its initial velocity v0:

v0x = v0cos10 = 24.6 m/s

v0y = v0sin10 = 4.34 m/s

The ball reaches its peak when vy = 0. Let's calculate the time it takes for vy to become zero:

vy = v0y - gt ---> t = v0y/g = 0.44 s

The horizontal distance it travels in this time is

x = v0xt = (24.6 m/s)(0.44 s)

= 10.8 m

Note that the net is 15 m away. After traveling a horizontal distance of 10.8 m, the height of the ball is

y = -(1/2)gt^2 + v0yt + 2.1

= -(4.9 m/s^2)(0.44 s)^2 + (4.34 m/s)(0.44 s) + 2.1 m

= -0.95 m + 1.9 m + 2.1 m

= 3.05 m

Note that this is the height of the ball at its peak. While the ball is well above the net at its peak, it is well short of its required horizontal distance to clear it. Instead, let's find the time it takes for the tennis ball to travel a horizontal distance of 15 m first:

x = v0xt ----> t = x/v0x = (15 m)/(24.6 m/s) = 0.61 s

Then calculate the height y when t = 0.61 s. If y > 0.9 m (height of the net), then the ball will clear the net.

y = -4.9t^2 + v0yt + 2.1

= -4.9(0.61 s)^2 + (4.34 m/s)(0.61 s) + 2.1 m

= -1.82 m + 2.65 m + 2.1 m

= 2.93 m

Yes, the ball will clear the net by 2.03 m.

3 0

3 years ago