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3 years ago

Is crumpling a sheet of paper a physical or chemical change? Why?

2 answers:

7 0

Crumpling a sheet of paper would be physical change. Only the appearance of the paper changes. The makeup of the paper is not being altered.

rjkz [21]3 years ago

3 0

Hi there!

Crumpling a piece of paper is a physical change.

Since there aren't any types of chemical reactions or chemical substance reactions when you crumple a piece of paper, it is a physical change.

Hope this helps!

You might be interested in

What 2 kinds of substances does convection occur ?

ch4aika [34]

Liquids and Gases

Explanation:

Convection is a form of heat transfer that is predominant in liquids and gaseous substances. This form of heat transfer is driven by density differences between gases and liquids.

Convection involves the actual movement of the particles of a medium.
Boiling of food is clinical example of convection in liquids. Hot part of the food in contact with the heat source becomes less dense and more buoyant. They rise to the top of the medium and are replace by the denser and colder part of the food.
Land and sea breeze is an example of convection in gases. The land warms the air around it during the day. It is hotter and less dense. The air mass moves to replace the ones on the sea where the air is relatively cold due to high specific heat capacity of water.
The reverse process occurs at night.

Learn more:

Heat transfer from the sun brainly.com/question/1140127

#learnwithBrainly

4 0

3 years ago

Compare a change in temperature of 1°C to a change of 1°F.

NikAS [45]

Answer:

A change of one degree Celsius = a change of one Kelvin, but a Celsius temperature is never equal to a Kelvin temperature. A change of 1 degree Fahrenheit equals a change of 5/9 = 0.56 degrees Celsius. To convert a Fahrenheit temperature to Celsius, subtract 32 and multiply by 5/9.

Explanation:

5 0

3 years ago

Read 2 more answers

A Christmas light is made to flash via the discharge of a capacitor. The effective duration of the flash is 0.25 s (which you ca

Sonbull [250]

Answer:

The correct solution is:

(a) $1.375\times 10^{-2} \ J$

(b) $4.43\times 10^{-3} \ C$

(c) $1.42\times 10^{-3} \ F$

(d) $178.57 \ \Omega$

Explanation:

The given values are:

Effective duration of the flash,

ζ = 0.25 s

Average power,

$P_{avg}=55 \ mW$

$=55\times 10^{-3} \ W$

Average voltage,

$V_{avg}=3.1 \ V$

Now,

(a)

⇒ $E=P_{avg}\times \zeta$

On substituting the values, we get

⇒ $=55\times 10^{-3}\times 0.25$

⇒ $=1.375\times 10^{-2} \ J$

(b)

⇒ $E=Q\times V_{avg}$

then,

⇒ $Q=\frac{E}{V_{avg}}$

On substituting the values, we get

⇒ $=\frac{1.375\times 10^{-2}}{3.1}$

⇒ $=4.43\times 10^{-3} \ C$

(c)

⇒ $C=\frac{Q}{V}$

⇒ $=\frac{4.43\times 10^{-3}}{3.1}$

⇒ $=1.42\times 10^{-3} \ F$

(d)

As we know,

⇒ $R=\frac{1}{4C}$

⇒ $=\frac{1}{4\times 1.42\times 10^{-3}}$

⇒ $=\frac{1000}{5.6}$

⇒ $=178.57 \ \Omega$

5 0

2 years ago

This is a form of energy representing the motion of the molecules which make up an object. A. Thermal Energy B. Kinetic Energy C

bija089 [108]

Answer:

Kinetic energy.

Explanation:

There are many kinds of energy. Some of them are kinetic energy, potential energy, thermal energy etc.
The energy that shows the motion of the object is called its kinetic energy.
Also, the sum of kinetic energy and the gravitational potential energy is called mechanical energy.
Out of the given options, kinetic energy is the form of energy that represents the motion of the molecules which make up an object.
Hence, the correct option is (B).

4 0

3 years ago

A stationary siren creates an 894 Hz

valentina_108 [34]

Answer:

12.3 m/s

Explanation:

The Doppler equation describes how sound frequency depends on relative velocities:

fr = fs (c + vr)/(c + vs),

where fr is the frequency heard by the receiver,

fs is the frequency emitted at the source,

c is the speed of sound,

vr is the velocity of the receiver,

and vs is the velocity of the source.

Note: vr is positive if the receiver is moving towards the source, negative if away.

Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.

Given:

fs = 894 Hz

fr = 926 Hz

c = 343 m/s

vs = 0 m/s

Find: vr

926 = 894 (343 + vr) / (343 + 0)

vr = 12.3

The speed of the car is 12.3 m/s.

5 0

3 years ago