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3 years ago

Using definitions and examples compare chemical and physical changes.

1 answer:

8 0

"There are several differences between a physical and chemical change in matter or substances. A physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed."

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I WILL MARK YOU THE BRAINLIEST

mr Goodwill [35]

Explanation:

700N right

to get the net force

you gotta let one direction be the negative ( the smaller force)

so the total force towards the left is 100N ( 60 + 40= 100)

which is smaller than the right force which is 800 N so you let 100 N be negative

so without even calculating , you can know that it will be moving towards the right because right force > left force

your add both forces ( remember 100 N is negative)

so 800N + ( - 100N)

= 700N

towards the right

hope this helps

this is just one method that helped me understand

please mark it brainliest

3 0

3 years ago

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A 1.0-μm-diameter oil droplet (density 900 kg/m3) is negatively charged with the addition of 39 extra electrons. It is released

GREYUIT [131]

Answer:

$6.75\mu C/m^2$

Explanation:

We are given that

Diameter,d= $1\mu m=1\time 10^{-6} m$

$1\mu m=10^{-6} m$

Radius,r= $\frac{d}{2}=\frac{1}{2}\times 10^{-6}=0.5 \times 10^{-6} m$

Density, $\rho=900kg/m^3$

Total number of electrons,n=39

Charge on electron = $1.6\times 10^{-19} C$

Total charge= $q=ne=39\times 1.6\times 10^{-19}=62.4\times 10^{-19} C$

Distance,s=2mm= $2\times 10^{-3} m$

Mass = $density\times volume=900\times \frac{4}{3}\pi r^3=900\times \frac{4}{3}\pi(0.5\times 10^{-6})^3=4.7\times 10^{-16} kg$

Initial velocity,u=0

Final speed,v=4.5 m/s

$v^2-u^2=2as$

$(4.5)^2-0=2a(2\times 10^{-3})$

$20.25=4a\times 10^{-3}$

$a=\frac{20.25}{4\times 10^{-3}}=5062.5m/s^2$

Force,F=ma

$qE=ma$

$q(\frac{\sigma}{2\epsilon_0})=ma$

$\sigma=\frac{2\epsilon_0ma}{q}=\frac{2\times 8.85\times 10^{-12}\times 4.7\times 10^{-16}\times 5062.5}{62.4\times 10^{-19}}$

$\epsilon_0=8.85\times 10^{-12}$

$\sigma=6.75\times 10^{-6}C/m^2=6.75\mu C/m^2$

6 0

3 years ago

A planet moves fastest in its orbit around the sun when it is at which position?

Nesterboy [21]

Answer:

When it's closest to the sun.

Explanation:

The force of gravity acting on a planet is equal to its mass times its centripetal acceleration.

Fg = m v^2 / r

The force of gravity is defined by Newton's law of universal gravitation as:

Fg = mMG / r^2

Therefore:

mMG / r^2 = m v^2 / r

MG / r = v^2

v increases as r decreases. So the planet is moving fastest when it's closest to the sun, also known as the <em>perihelion</em>.

6 0

3 years ago

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If youre going 70 miles an hour for 70 miles, how long would it take you to travel those 70 miles

Anna11 [10]

490 miles in total ur welcome

6 0

3 years ago

Five race cars speed toward the finish line at the Jasper County Speedway. The table lists each car’s speed in meters/second. If

Anarel [89]

I think the answer would be Car C.

7 0

3 years ago

Read 2 more answers