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3 years ago

Why did John Dalton describe atoms as solid spheres, and did he think all spheres were the same?

1 answer:

8 0

Go here to get some help now a=can you help me i posted it on your profile

https://www.khanacademy.org/science/chemistry/electronic-structure-of-atoms/history-of-atomic-struct...

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What is one way to model gravity and magnetism

Oxana [17]

Answer:

Gravity and magnetism are not the same thing. In fact, they are completely separate forces. Gravity is a force that acts between any two objects with mass. ... Magnetism can either pull the two objects together or push them apart, depending on which way the magnets point.

Explanation:

6 0

3 years ago

Read 2 more answers

A ball is launched vertically with an initial speed of y˙0= 50 m/s, and its acceleration is governed by y¨=-g-cDy˙2, where the a

stira [4]

Answer:

Explanation:

Given

acceleration is given by

$a=-g-c_Dv^2$

where $\ddot{y}=a$

$\dot{y}=v$

Also acceleration is given by

$a=v\frac{\mathrm{d} v}{\mathrm{d} s}$

$ds=\frac{v}{a}dv$

$\int ds=\int \frac{v}{-g-0.001v^2}dv$

$\Rightarrow Let -g-0.001v^2=t$

$-0.001\times 2vdv=dt$

$vdv=-\frac{dt}{0.002}$

$at\ v_0=50\ m/s,\ t=-g-0.001(50)^2$

$t=-g-2.5$

at $v=0,\ t=-g$

$\int_{0}^{s}ds=\int_{-g}^{-g-2.5}\frac{-dt}{0.002t}$

$\int_{0}^{s}ds=\int^{-g}_{-g-2.5}\frac{dt}{0.002t}$

$s=\frac{1}{0.002}lnt|_{-g}^{-g-2.5}$

$s=\frac{1}{0.002}\ln (\frac{g+2.5}{g})$

$s=113.608\ m$

when air drag is neglected maximum height reached is

$h=\frac{v_0^2}{2g}$

$h=\frac{50^2}{2\times 9.8}$

$h=127.55\ m$

3 0

3 years ago

A metal coin has a volume of 835 mm3 and a mass of 5.67 g. What is the density of the coin?

Lilit [14]

Density formula: d = M/V
So I think the answer would be 5.67/ 835 I am not sure of the answer I got confused (´∀｀) but I hope it will help

3 0

2 years ago

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Why is it important to understand the concept of density ?

N76 [4]

Density applies to many if not all aspects of life. With density you can explain why ice floats. You can explain why oxygen is on the earth, and not floating around in space( or being replaced by another gas). You can also explain why heat rises while cold air sinks.

8 0

2 years ago

A person drives 20 miles north and 45 miles east. What is the angle of the resultant straight to their destination?

Alex787 [66]

Let us take east and north as the positive x and y-axes should the motion be plotted in a cartesian plane. Thus, the x value is 45 miles and the y value is 20. The tangent of an angle is equal to the ratio of y to x.

tanθ = y / x

Substituting,

tanθ = 20/45 = 0.44

The value of θ is 23.96°.

7 0

2 years ago