Answer please in comment what i am typing

An empty coal car of a train of mass 8000 kg is moving at 12 m/s along rails. 24000 kg of coal is dumped into the car from a mot

ZanzabumX [31]

Answer:

3 m/s

Explanation:

Initial = Final

Mass * Velocity = Mass *Velocity

8000kg * 12m/s = (8000kg+ 24000kg) * (Final Velocity)

(96000 kgm/s) / (32000kg) = (Final Velocity)

Final Velocity = 3 m/s

7 0

2 years ago

Masses in the universe curve space-time. What does the resulting shape of space-time cause?

swat32

I think the answer is D: gravity

7 0

3 years ago

WILL GIVE THE BRAINLEST

Leona [35]

<h2>Question no. 1: </h2><h3>Answer: </h3>

Controlled experiment is an experiment which is designed to test a variable, which can be changed during the experiment.

<h3>Explanation: </h3>

Hence in this experiment, the importance of experiment is being tested, as it is added only in one set of plant.

A manipulated variable is an independent variable whose amount can be changed during an experiment.

Here the fertilizer is a manipulated variable.

<h2>Question 2: </h2><h3>Answer: </h3>

Because theory is the most organised statement proved by a set of independent experiments.

<h3>Explanation: </h3>

Hypothesis is the initial idea on which basis different experiments are conducted. But if 1 experiment succeeded and it supports the hypothesis, hypothesis do not become a theory.

For a theory, different experiments are necessary which supports that hypothesis.

<h2>Question no 4. </h2><h3>Answer: </h3>

Density = 1.909 kg/m3

<h2>Explanation: </h2>

Given data:

Mass of the object = 42 kg

Volume of the object = 22 m3

Density of the object = ?

Solution

Density = mass/volume

Density =42/22 = 1.909

Density = 1.909 kg/m3

<u><em>Hence the density of the object is 1.909 and its unit is kg/m3 which is system international unit of density. </em></u>

<h2>Question 5. </h2><h3>Answer: </h3>

Chlorine and water in swimming pool are mixed in such a way that there composition remains same throughout the mixture. And chlorine cannot be separated back from water. This is the homogeneous mixture.

<h3>Explanation: </h3>

A homogeneous mixture is a mixture of more than one substance which are mixed together in such a way that they cannot be separated and the composition of the mixture remains same throughout the mixture.
Example of homogeneous solution is sugar solution in water.
As for swimming pool cleaning chlorine is added in pool water, it mixes in the whole water by diffusion. Hence it is a homogeneous mixture.

<h2>Question no. 6. </h2><h3>Answer: </h3>

Because physical change does not include composition change, it includes change in physical parameters. And in splicing tomato only change in shape is done.

<h3>Explanation: </h3>

Chemical change means irreversible chemical composition change like the burning of toast.
Physical change means reversible or irreversible change in shape, volume density without change in chemical composition.
Splicing tomato comes under 2nd category because it does not include chemical change.

Remaining questions are attached in the files.

<h2 />

Download pdf

3 0

3 years ago

A wave is described by the expression y(x, t)= (3.0 cm) × cos(1.5x − 50t), where x is in m and t is in s.

Nadya [2.5K]

Answer:

Speed = 209.5m/s

Direction = Positive x direction

Explanation:

The general wave equation expressing the displacement of a wave travelling in the positive x-direction is written as follows;

y(x, t) = y x cos(2 $\pi$ kx - 2 $\pi$ ft) --------------------(i)

Where;

y(x, t) = the position of the wave at time t

y = the amplitude of the wave,

k = the wave number

f = frequency of the wave

Given;

y(x, t)= (3.0 cm) × cos(1.5x − 50t) -------------------(ii)

Comparing equations(i) and (ii)

=> y = amplitude

=> y = 3.0cm

=> y = 0.03m

Also,

=> 2 $\pi$ kx = 1.5x

=> k = $\frac{0.75}{\pi }$

=> wave number (k) = $\frac{0.75}{\pi }$

Also,

=> 50t = 2 $\pi$ ft

=> f = frequency

=> f = $\frac{25}{\pi }$ Hz

But,

=> wavelength (λ) = $\frac{2\pi }{k}$ ------- (iii)

Substituting for k = $\frac{0.75}{\pi }$ in equation (iii)

=> λ = (2 $\pi$ ) ÷ $\frac{0.75}{\pi }$

=> λ = (2 $\pi$ ) x $\frac{\pi }{0.75}$ (where $\pi$ = 3.142)

=> λ = 26.33m

(a) To calculate the speed (v) of the wave, we use the formula;

v = f x λ

where f = $\frac{25}{\pi }$ and λ = 26.33

=> v = $\frac{25}{\pi }$ x 26.33

=> v = 209.5m/s

(b) To get the direction in which the wave is travelling, a quick look at the sign between the x and t terms (1.5x - 50t) in the given equation (ii) will suffice.

<em>A negative sign shows that the wave is travelling in the +x direction</em>

<em>A positive sign shows that the wave is travelling in the -x direction.</em>

In this case, the sign between these terms is negative. This shows that the wave is travelling in the positive x direction.

8 0

3 years ago

Which section of the reaction represents the reactants? A) a B) b C) c D) d

ivann1987 [24]

This question is incomplete, but I can do it for you, considering the equation to be *In its most famous form*:
A+B⇒C+D
A and B here are the reactants, while C and D are the products.
The reactants are generally the input materials in the beginning of any chemical reactions and they usually, if not always, are on the left hand side of the chemical equation. While the products are on the right hand side and are the final output of the chemical reaction.

Hope this helps.

3 0

3 years ago

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