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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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What is the total amount of force needed to keep a 6.0 kg object moving at speed

DanielleElmas [232]

Answer:

C. 0 N

Explanation:

In the absence of external forces, a body in motion will stay in motion.

F = ma

F = 6.0(0) = 0

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2 years ago

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How much force is needed to accelerate a 2500 kg car at a rate of 3.5 m/s^2?

Sati [7]

F = ma

F = applied force in newtons = to be determined

m = mass of the car = 2,500 kg

a = acceleration of the car = 3.5 m/s²

F = (2,500 kg)(3.5 m/s²)

F =8750

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3 years ago

A proton is released in a uniform electric field, and it experiences an electric force of 5 X 10^-10 N toward the South. What is

Ymorist [56]

Answer:

Electric field on proton

$E=3.12\times 10^9\ N/C$

Explanation:

Given that

$Force,F=5\times 10^{-10}\ N$

We know that

Charge on proton

$q=1.6\times 10^{-19}\ C$

We know that

Force = Electric field x Charge

F= E x q

$E=\dfrac{F}{q}\ N/C$

$E=\dfrac{5\times 10^{-10}}{1.6\times 10^{-19}}\ N/C$

$E=3.12\times 10^9\ N/C$

Electric field on proton

$E=3.12\times 10^9\ N/C$

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2 years ago

A smooth circular hoop with a radius of 0.800 m is placed flat on the floor. A 0.300-kg particle slides around the inside edge o

Marrrta [24]

Answer:

a)11.25 J

b)Number of revolution = 1

Explanation:

Given that

Radius ,r= 0.8 m

m= 0.3 kg

Initial speed ,u= 10 m/s

final speed ,v= 5 m/s

Initial energy

$KE_i=\dfrac{1}{2}mu^2$

$KE_i=\dfrac{1}{2}0.3\times 10^2$

KEi= 15 J

Final kinetic energy

$KE_f=\dfrac{1}{2}mv^2$

$KE_f=\dfrac{1}{2}0.3\times 5^2$

KEf=3.75 J

The energy transformed from mechanical to internal = 15 - 3.75 J = 11.25 J

The minimum value to complete the circular arc

$V=\sqrt{r.g}$

Now by putting the values

$V=\sqrt{0.8\times 10}$

V= 2.82 m/s

So kinetic energy KE

$KE=\dfrac{1}{2}mV^2$

$KE=\dfrac{1}{2}0.3\times 2.82^2$

KE=1.19 J

ΔKE= KEi - KE

ΔKE= 15- 1.19 J

ΔKE=13.80 J

The minimum energy required to complete 2 revolutions = 2 x 11.25 J

= 22.5 J

Here 22.5 J is greater than 13.8 J.So the particle will complete only one revolution.

Number of revolution = 1

4 0

2 years ago

Please help me with a speech.The topic of my speech is Passion.

Vikentia [17]

Answer:

Explanation:

Passion

For me, standing on the summit of Mt Everest was the result of following a process. The process of mountaineering. I love mountaineering. I am passionate about it. I love the months of planning for an expedition, the months of sweating and training to prepare my body physically. The meticulous preparation of my equipment. Most of all I love the huge mental challenge I have to overcome before each climb to confront my own fear. All these reasons are why I climb, they are why I climbed Mt Everest and that is why I continue to climb.

Passion is an enormously powerful force. It gives us the strength to get through hard times and setbacks. It gives us strength to overcome our fears, to ignore what other people think of us, to be disciplined and make sacrifices in pursuit of our dreams. Passionate people do not want to take shortcuts – they consider that ‘learning the process’ is an important part of the journey.

In mountaineering it’s easy to spot those who are not passionate about the process. They want to stand on top of the mountain but they are not really interested in the process of climbing the mountain. I feel for these people. Success without hard work is a hollow, empty feeling. They never last long in the sport.

Just as in life, successful mountaineers are the ones who are passionate. They are not there just to stand on the summit. Their passion gives them the energy to work the hardest, fight the longest, and in the words of Winston Churchill “never, never. never give-up”.

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2 years ago