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ch4aika [34]
3 years ago
13

It takes light from the closest star to Earth (other than the Sun) about four years to reach Earth. If intelligent life were on

a planet circling that star, how long would it take for scientists on Earth to send them a radio transmission and for the scientists to receive their reply?
Physics
1 answer:
mafiozo [28]3 years ago
4 0

If the intelligent aliens on that distant planet could receive our signal, and then reply to us INSTANTLY with no delay, then our Scientists on Earth would hear the response <em>eight years after</em> they sent their original greeting.

Light and radio waves both travel through space at the same speed.  If our scientists sent a radio transmission to that distant planet, it would take four years for the radio message to get there and be heard.  Any response would take four years to travel back to us.  If the aliens didn't dilly-dally and sent their response immediately, the round trip would total up to eight years.  

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A block is given an initial velocity of 8.0 m/s up a frictionless 28° inclined plane. (a) What is its velocity when it reaches t
kramer

Answer:

A.) 8 m/s

B.) 7.0 m

Explanation:

Given that a block is given an initial velocity of 8.0 m/s up a frictionless 28° inclined plane.

(a) What is its velocity when it reaches the top of the plane?

Since the plane is frictionless, the final velocity V will be the same as 8 m/s

The velocity will be 8 m/s as it reaches the top of the plane.

(b) How far horizontally does it land after it leaves the plane?

For frictionless plane,

a = gsinø

Acceleration a = 9.8sin28

Acceleration a = 4.6 m/s^2

Using the third equation of motion

V^2 = U^2 - 2as

Substitute the a and the U into the equation. Where V = 0

0 = 8^2 - 2 × 4.6 × S

9.2S = 64

S = 64/9.2

S = 6.956 m

S = 7.0 m

4 0
3 years ago
an astronaut on earth notes that in her soft drink an ice cube floats with 9/10 of its volume submerged. if she were instead in
nadya68 [22]

The gravitation force is 1/6 that of earth, and the ice in the same soft drink would float with 9/10 submerged option (B) is correct.

<h3>What is gravitational force?</h3>

All mass-bearing objects are attracted by gravitational force. Because it consistently attempts to bring masses together rather than push them apart, the gravitational force is referred to as attractive.

As we know, the gravitational force is given by:

\rm F = \dfrac{Gm_1m_2}{r^2}

Where G is the gravitational constant.

m1 and m2 are masses.

r is the distance between the masses.

Weight of ice cube = weight of soft drink displaced

mg = ρVg

m = ρV

g does not affect astronauts on earth in a lunar module.

Thus, the gravitation force is 1/6 that of earth, and the ice in the same soft drink would float with 9/10 submerged option (B) is correct.

An astronaut on Earth notes that in her soft drink an ice cube floats with 9/10 of its volume submerged. If she were instead in a lunar module parked on the Moon where the gravitation force is 1/6 that of Earth, the ice in the same soft drink would float:A) with more than 9/10 submerged. B) with 9/10 submerged.C) with 6/10 submerged.D) totally submerged.

Learn more about the gravitational force here:

brainly.com/question/12528243

#SPJ1

3 0
2 years ago
What are two reasons why a home computer scanner requires
alexandr1967 [171]

Answer: C and D

Explanation: a p e x

4 0
3 years ago
Read 2 more answers
which one of the following is not an example of a combination reaction a. 2H2O(I)---&gt; 2H2(g)+O2(g) b. 2K+CI2---&gt;2KCI c. 2H
Alexxandr [17]
The answer would be A.

Combination reaction, otherwise known as synthesis reaction, occurs when two or more substances react and form a single, more complex substance.

A combination reaction looks like this in an equation:

                                     <em> A + B         </em><em>→       </em><em>AB</em>
                                   reactants              product

So from two reactants they become one product. 
Let's take a look at choice A.

                                   2H₂O(l)       →      2H₂(g) + O₂(g)
                                  reactant                     product(s)

Notice that from one substance, it broke down into two substances. So this is not a combination reaction. This is what you call a <em>decomposition reaction. </em>
6 0
3 years ago
Which of the following is an example of a chemical change?
bija089 [108]

HELLO THERE

THE ANSWER IS

D. A gas when vinegar and baking soda are mixed

EXTRA INFO: An exmaple of phyical change is sawing a piece of wood

BEST REGARDS QUEEN Z

HOPE THIS HELPS

5 0
3 years ago
Read 2 more answers
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