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2 years ago

Distinguish between physical and chemical changes. Include examples in your explanations.

Physics

1 answer:

hram777 [196]2 years ago

6 0

Answer:

Chemical changes are recognized when a substance changes its properties permanently and it cannot be the same substance as before.

Instead the physical changes implies that if you can return to the same substance through a reverse process.

Explanation:

A chemical change is, by example, a combustion, if a sheet of paper burns, its result is ashes, the ashes cannot go back to being a sheet of paper because its properties changed, heat energy was generated that changed matter permanently.

A physical change, by example, is that of freezing water, the water becomes ice, but this can easily become water again if the temperature is increased, its properties do not change and the chemistry of the substance does not change.

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How many mm are in a micro-m?

Dahasolnce [82]

For this case we have that by definition, a micrometer is equivalent to a thousandth of a millimeter, that is, 0.001 millimeters.

Then, in other words, we have 0.001 millimeters in a micrometer.

Answer:

In a micrometer there are 0.001 millimeters.

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2 years ago

A 2.3 kg particle-like object moves in a plane with velocity components vx = 40 m/s and vy = 75 m/s as it passes through the poi

Sonbull [250]

Answer:

(a) $\overrightarrow{L}=885.5\widehat{k}$

(b) $\overrightarrow{L}=1046.5\widehat{k}$

Explanation:

mass, m = 2.3 kg

vx = 40 m/s

vy = 75 m/s

(a) Angular momentum is given by

$\overrightarrow{L}=\overrightarrow{r}\times \overrightarrow{p}$

Where, p is the linear momentum and r is the position vector about which the angular momentum is calculated.

Here, $\overrightarrow{r}=3\widehat{i}-4\widehat{j}$

$\overrightarrow{p}=m\overrightarrow{v}$

$\overrightarrow{p}=2.3\left ( 40\widehat{i}+75\widehat{j} \right )$

$\overrightarrow{p}= 92\widehat{i}+172.5\widehat{j}$

So, the angular momentum

$\overrightarrow{L}=\left ( 3\widehat{i}-4\widehat{j} \right )\times\left ( 92\widehat{i}+172.5\widehat{j} \right )$

$\overrightarrow{L}=885.5\widehat{k}$

(b) Here, $\overrightarrow{r}=(3+2)\widehat{i}+(-4+2)\widehat{j}$

$\overrightarrow{r}=5\widehat{i}-2\widehat{j}$

$\overrightarrow{L}=\left ( 5\widehat{i}-2\widehat{j} \right )\times\left ( 92\widehat{i}+172.5\widehat{j} \right )$

$\overrightarrow{L}=1046.5\widehat{k}$

6 0

2 years ago

A(n) 0.5 kg soccer ball approaches a player horizontally with a speed of 10.6 m/s. The player illegally strikes the ball with he

Llana [10]

Answer: - 25.2 kgm/s

Explanation: The mass of the ball is 0.5kg, and the initial velocity = 10.6m/s.

The final velocity is in opposite direction of the initial hence final velocity (v) = - 19.9 m/s

Impulse = change in momentum = final momentum - initial momentum.

Final momentum = mass × final velocity

Final momentum = - 19.9 × 0.5

Final momentum = - 9.95 kgm/s

Initial momentum = mass × initial velocity

Initial momentum = 0.5 × 10.6 = 5.3kgm/s

Change in momentum = final momentum - initial momentum = - 19.9 - 5.3

Change in momentum = - 25.2 kgm/s

The negative sign implies that the change in momentum is the opposite direction relative to the first.

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2 years ago

A 4 V power source is connected in parallel to four resistors: 1, 2, 2, and 3. Find the total current.

Keith_Richards [23]

Answer:

Explanation:

Equivalent resistance is 1 / ((1/1) + (1/2) + (1/2) + (1/3)) = 3/7 Ω

I = V/R = 4(7/3) = 28/3 = 9.3 A

4 0

1 year ago

1) Write Newton's three laws of motion (20 points). 2) Define acceleration (20 points). 3) Write the Month and Day of the Assign

vaieri [72.5K]

Answer:

Hey

I have no idea when YOUR assignment is due.

Newtons 1rst law:

An object that has constant motion will remain at that speed unless acted on by an external force.

Newtons 2nd law:

F=ma (force=mass*acceleration)

Newtons 3rd law:

when a force is applied to an object, there will be an opposite but equal reaction.

Acceleration:

How much your speed increases/decreases per unit of time.

I wrote all that^

4 0

2 years ago