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3 years ago

PLEASE HELP!!! GIVING BRAINLIEST!! ill also answer questions that you have posted if you answer these correctly!!!! (40pts)

Physics

1 answer:

Sunny_sXe [5.5K]3 years ago

3 0

friction make non moving objects starts to move

true

there are different types of force which may help them to move

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1. Calculate the total heat content of 10 kg of ice at -23°C.?

vesna_86 [32]

To solve the problem, we must know the heat capacity of ice and water.

For Cp = 2090 J/kg C

H = mCpT

H = (10 kg) ( 2090 J/ Kg C) ( -23 C)

H = - 480700 J

For water Cp = 4180 j/kg C

H = (100 kg) ( 4180 J/kg C) ( 60 C)

8 0

3 years ago

Which of the following sets of characteristics describes the image formed by a plane mirror?A. Virtual and invertedB. Real and u

tiny-mole [99]

<h2>Answer: Virtual and upright</h2><h2 />

A plane mirror is a highly polished flat surface with a very high capacity to reflect incident light.

We can understand in a better way how this works with the figure attached:

1. The incident rays coming from the real object reach the mirror and

2.are reflected following the law of Reflection.

3.The prolongation of those reflected rays converge at a point that does not coincide with the actual position of the object. At that point the virtual image of the object is formed.

4.Then, the reflected divergent rays are captured by our eye converging on the retina.

Now, the image is said to be virtual because it is a copy of the object that looks as if the object is behind the mirror and not in front of it or on the surface, but it is not really there. However, it can be seen when we focus it with our eyes.

In addition, the image formed is:

symmetrical, because apparently it is at the same distance from the mirror

the same size as the object.

upright, because it retains the same orientation as the object.

4 0

3 years ago

A mechanic needs to replace the motor for a merry-go-round. The merry-go-round should accelerate from rest to 1.5 rad/s in 7.0 s

marta [7]

Answer

given,

initial speed of merry-go-round = 0 rad/s

final speed of merry-go-round = 1.5 rad/s

time = 7 s

Radius of the disk = 6 m

Mass of the merry-go-round = 25000 Kg

Moment of inertia of the disk

$I = \dfrac{1}{2}MR^2$

$I = \dfrac{1}{2}\times 25000\times 6^2$

I = 450000 kg.m²

angular acceleration

$\alpha = \dfrac{\omega_f-\omega_0}{t}$

$\alpha = \dfrac{1.5-0}{7}$

$\alpha =0.214\ rad/s^2$

we know,

$\tau= I \alpha$

$\tau= 450000\times 0.214$

$\tau=96300\ N.m$

8 0

3 years ago

If the resistivity of copper is less than that of gold at room temperature, which of the following statements must be true? Gold

KiRa [710]

Answer:

Gold Has A Higher Resistance Than Copper. The Sample Of Gold Is Thinner Than The Sample Of Copper. Electrons In Gold Are More Likely To Be Scattered Than Electrons In Copper At Room Temperature When they are exelerated by the same electric field.

Explanation:

5 0

3 years ago

what is the density of a substance that has a mass of 2.0 g , and when placed in a graduated cylinder the volume changed from 70

lubasha [3.4K]

A material with a mass of 2.0 g when placed in a graduated cylinder the volume changed from 70 ml to 75 ml has a density of 0.4 g/mL.

How do I calculate the substance's density?

We'll start by getting the substance's volume. This is attainable as follows:

Water volume: 70 mL

75 mL = volume of material + water.

Substance volume =?

Substance volume equals (substance volume plus water) - (Volume of water)

Substance volume = 75 - 70

5 mL is the substance's volume.

Finally, we will calculate the substance's density. Below is an example to help:

2.0 g is the substance's mass.

5 mL is the substance's volume.

Substance density =?

Mass / volume equals density.

Substance density = 2/5

0.4 g/mL is the substance's density.

The density is therefore 0.4 g/mL.

To know more about density, visit:

brainly.com/question/952755

#SPJ4

6 0

1 year ago