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lorasvet [3.4K]

3 years ago

15

A moving car initially has kinetic energy K. The car then moves in the opposite direction with four times its initial speed. Wha

t is the kinetic energy now

1 answer:

Liula [17]3 years ago

6 0

If initial speed was v, Kinetic energy was K = 1/2mv^2

When speed will be 4v, KE will be:

= 1/2 m (4v)^2

=1/2m 16 v^2

=16K

Now kinetic energy will become <em>1</em><em>6</em><em> </em><em>times</em><em> </em><em>of</em><em> </em><em>initial</em><em> </em><em>Kinetic</em><em> </em><em>Energy</em>

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If the velocity of a proton is straight up (thumb pointing up) then RHR2 shows that the force points to the left. What would the

diamong [38]

Answer:

a) to the right

b) up

c) down

d) there will be no force on the proton

e) there will be no force on the proton

Explanation:

The complete question is

If the velocity of a proton is straight up(thumb pointing up) then RHR2 (right hand rule) shows that the force points to the left. What would the direction of the force be if the velocity were a)down, b)to the right, c)to the left, d)into the page, and e)out of the page?

The right hand rule for a positive charge states that...

Hold the thumb of the right hand at right angle to the rest of the fingers, and the rest of the fingers parallel to one another, and pointing away from the body. If the thumb shows the velocity of a positive charge in a magnetic field, and the fingers all point in the direction of the magnetic field, then the palm will push in the direction of the force on the positive charge (proton).

From this, we can deduce from the original statement about this proton that the direction of the field is into the screen of this computer. with that field direction held constant, we can work out that

a) if the thumb point down, the force will be to the right

b) if the thumb points to the right, the force will be upwards

c) if the thumb points to the left, the force is downwards

d) if the thumb points into the page, then there will be no force on the proton since the proton must travel perpendicularly to the magnetic field for a force to be induced on it

e) explanation is the same as foe option d.

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3 years ago

What phenomenon causes the fuzzy image? What kind of lens is used to correct this, and how is it corrected?

mamaluj [8]

In optics, chromatic aberration (abbreviated CA; also called chromatic distortion and spherochromatism) is an effect resulting from dispersion in which there is a failure of a lens to focus all colors to the same convergence point.[1] It occurs because lenses have different refractive indices for different wavelengths of light. The refractive index of transparent materials decreases with increasing wavelength in degrees unique to each.

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3 years ago

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When bitten by an animal, one should:

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Answer:

consider rabies injections if the animal is not found

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Complete the graphic organizer by telling what the advantages and disadvantages of each type of renewable energy are. (Look in p

inysia [295]

Answer:

PRO'S OF SOLAR ENERGY: reduced electricity bills, low maintenance cost, renewable energy source.

CONS OF SOLAR ENERGY: Cost, relies on weather, takes up a lot of space.

PROS OF WIND ENERGY: Clean environment, cost effective, Free

CON'S OF WIND ENERGY: Wind turbines are noisy, strength of wind is not always reliable

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CONS OF GEOTHERMAL ENERGY: Greenhouse emission, high investment cost, requires a lot of land.

PROS OF BIOMASS ENERGY: Reduced dependence on fossil fuels, carbon neutral, waste reduction.

CONS OF BIOMASS ENERGY: Emissions, deforestation. cost.

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6 0

3 years ago

You're having a hard time pushing a refrigerator across the kitchen floor. The force of your own push is 993 N. The force of fri

Helen [10]

Answer:

The acceleration of the refrigerator is $a= 0.056 ms^{-2}$

Explanation:

The expression of the equation of the net force acting on the refrigerator is as follows;

F-f= ma

Here, F is the applied force, f is the force of friction, m is the mass and a is the acceleration.

It is given in the problem that you're having a hard time pushing a refrigerator having mass 355 kg across the kitchen floor. The force of your own push is 993 N. The force of friction opposing your own push is 973 N.

Put F= 993, f= 973 N and m = 355 kg in the above expression of the equation to calculate the acceleration of the refrigerator.

993 - 973 = (355)a

20 = 355 a

$a= 0.056 ms^{-2}$

Therefore, the acceleration of the refrigerator is $a= 0.056 ms^{-2}$ .

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3 years ago