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3 years ago

HURRY WILL GIVE BRAINLIEST

Physics

1 answer:

andrey2020 [161]3 years ago

8 0

The amount of energy needed to melt the ice is 1670 J

Explanation:

The amount of thermal energy needed to completely melt a certain amount of solid substance (already at melting point) is given by

$Q=m\lambda_f$

where

m is the amount of the substance

$\lambda_f$ is the specific latent heat of fusion of the substance

Here, the mass of the ice is

m = 5 g = 0.005 kg

And the specific latent heat of fusion of ice is

$\lambda_f = 334,000 J/kg$

Assuming that the ice is already at melting point, the thermal energy needed to melt the ice is

$Q=(0.005)(334,000)=1670 J$

Learn more about specific heat:

brainly.com/question/3032746

brainly.com/question/4759369

#LearnwithBrainly

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NNADVOKAT [17]

Answer:

B. Air

Explanation:

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3 years ago

What is the difference between the specific heat of a substance and the total amount of heat of that substance ?

Dominik [7]

Explanation:

Specific heat of a substance is defined as the amount of heat that is required to raise the temperature of one mole or mass of a substance by 1°C.

The total amount of heat of a substance is the amount of heat required to raise the temperature of the given mass of the substance by 1°C.

Specific heat is an intensive property and does not depend on the amount of matter that is present within a substance.

Total amount of heat is an extensive property of matter and it is predicated on the amount of matter present.

6 0

3 years ago

Megan was doing time trials on her bike around a 400m horizontal track. She took 32 seconds to travel 400m. What was her average

Mars2501 [29]

To find average speed, we divide the distance of travel (in this case, 400 metres) by the time she took, 32 seconds. Therefore: 12.5 seconds is her average speed.

5 0

3 years ago

Read 2 more answers

Mention a few precautions to be taken at the time of spraying the pesticides

denpristay [2]

Pesticides are nothing but strong chemicals that kill the pests.

They are harmful for human also.

While spraying, the pesticide mixes with the air and enters the farmer’s body who is spraying.

Inside the body this chemical gets mixed with the blood and affects the immune system.

As a result the farmer falls ill.

So it is important that the person who is spraying pesticide mush cover his mouth and nose to protect himself from its harmful effect.

3 0

3 years ago

A point charge with charge q1 = 4.00 μC is held stationary at the origin. A second point charge with charge q2 = -4.40 μC moves

Bezzdna [24]

Answer:

W=0.94J

Explanation:

Electrostatic potential energy is the energy that results from the position of a charge in an electric field. Therefore, the work done to move a charge from point 1 to point 2 will be the change in electrostatic potential energy between point 1 and point 2.

This energy is given by:

$U=\frac{K\left |q_1 \right |\left |q_2 \right |}{r}\\$

So, the work done to move the chargue is:

$W=U_1-U_2\\W=\frac{K\left |q_1 \right |\left |q_2 \right |}{r_1}-\frac{K\left |q_1 \right |\left |q_2 \right |}{r_2}\\r_1=\sqrt{((0.155 m)^2+0 m)^2}=0.115m\\r_2=\sqrt{((0.245 m)^2+(0.270 m)^2}=0.365m\\W=K\left |q_1 \right |\left |q_2 \right |(\frac{1}{r_1}-\frac{1}{r_2})\\W=8.99*10^9\frac{Nm^2}{c^2}(4.00*10^{-6}C)(4.40*10^{-6}C)(\frac{1}{0.115m}-\frac{1}{0.365})\\W=0.94J$

The work is positive since the potential energy in 1 is greater than 2.

5 0

4 years ago