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3 years ago

3. Pedro threw a penny into a fountain and it sank to the bottom. Which of the following would explain

Physics

2 answers:

solong [7]3 years ago

4 0

Answer:

Explanation:

A is not correct as there is much more water then penny meaning the water has more mass. The same can be said about C as the water also has more volume. Answer D is incorrect as the temperature of the penny is irrelevant to its ability to sink. That leaves us with option B, which is true as the penny is composed of metal allowing it to sink in the water due to having more density.

____ [38]3 years ago

3 0

Answer:

its B because we're not talking about mass even tho most people would have chosen A cuz it says mass and u they would think its apart of density but if ur testing to see density ur figuring out which object will sink and which one will float so da reason why da penny snuck it cuz da density is greater den da water and copper has a better chance of sinking den floating so dats why its B I hope dis helps :3

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What's a refractive medium that focuses light to a single point?

ss7ja [257]

Answer:

The convex lens is shaped so that all light rays that enter it parallel to its axis cross one another at a single point on the opposite side of the lens.

Explanation:

3 0

3 years ago

A 34.0 %-efficient electric power plant produces 800 MW of electric power and discharges waste heat into 20∘C ocean water. Suppo

mojhsa [17]

Answer:

77647

Explanation:

$\eta$ = Efficiency = 34%

Power used in 1 home = 0.02 MW

Total power is

$P=\dfrac{800}{\eta}\\\Rightarrow P=\dfrac{800}{0.34}\\\Rightarrow P=2352.94117\ MW$

Waste of power

$2352.94117-800=1552.94117\ W$

Number of homes would be given by

$n=\dfrac{1552.94117}{0.02}=77647.0585\ homes$

The number of homes that could be heated with the waste heat of this one power plant is 77647

8 0

3 years ago

Consider the Uniform Circular Motion Gizmo configured as shown. Notice that, under the current settings, |a|=0.50m/s2. What chan

Eddi Din [679]

To increase the centripetal acceleration to $2.00 m/s^2$ , you can double the speed or decrease the radius by 1/4

Explanation:

An object is said to be in uniform circular motion when it is moving at a constant speed in a circular path.

The acceleration of an object in uniform circular motion is called centripetal acceleration, and it is given by

$a=\frac{v^2}{r}$

where

v is the speed of the object

r is the radius of the circular path

In the problem, the original centripetal acceleration is

$a=0.50 m/s^2$

We want to increase it by a factor of 4, i.e. to

$a'=2.00 m/s^2$

We notice that the centripetal acceleration is proportional to the square of the speed and inversely proportional to the radius, so we can do as follows:

- We can double the speed:

v' = 2v

This way, the new acceleration is

$a'=\frac{(2v)^2}{r}=4(\frac{v^2}{r})=4a$

so, 4 times the original acceleration

- We can decrease the radius to 1/4 of its original value:

$r'=\frac{1}{4}r$

So the new acceleration is

$a'=\frac{v^2}{(r/4)}=4(\frac{v^2}{r})=4a$

so, the acceleration has increased by a factor 4 again.

Learn more about centripetal acceleration:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

5 0

3 years ago

A wave is 8 meters long and has a frequency of 3 Hz. Find speed

Olenka [21]

Answer:

The speed is 24 $\frac{meter}{s}$

Explanation:

A wave is a disturbance that propagates through a certain medium or in a vacuum, with transport of energy but without transport of matter.

The wavelength is the minimum distance between two successive points of the wave that are in the same state of vibration. It is expressed in units of length (m).

Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

The speed of propagation is the speed with which the wave propagates in the middle, that is, the magnitude that measures the speed at which the wave disturbance propagates along its displacement. Relate wavelength (λ) and frequency (f) inversely proportionally using the following equation:

v = f * λ.

In this case, λ= 8 meter and f= 3 Hz

Then:

v= 3 Hz* 8 meter

So:

v= 24 $\frac{meter}{s}$

The speed is 24 $\frac{meter}{s}$

5 0

3 years ago

A 5 kg ball is sitting on top of a hill. It has a Potential Energy of 6000J. What is the height of the ball?

natali 33 [55]

Explanation:

mass=5 kg

potential energy=6000j

height=?

Now

potential energy =m.g.h

or 6000=5*9.8*h

or 6000=49h

or 6000÷49=h

or h= 122.45m

6 0

3 years ago