Using a simple machine the simple machine cannot increase the amount of ___,but can increase the amount of ___

Depth of a pond seems shallower than real depth,why?

IgorLugansk [536]

Answer:

The refraction of light at the surface of water makes ponds and swimming pools appear shallower than they really are. A 1m deep pond would only appear to be 0.75 m deep when viewed from directly above. When light emerges from glass or water into air it speeds up again.

Explanation:

7 0

3 years ago

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numerade A 62 kg bungee jumper jumps from a bridge. She is tied to a bungee cord whose unstretched length is 12 m. She falls a t

GalinKa [24]

Answer:

k = 104.5 N/m

Explanation:

When she reaches the lowest point the velocity of the jumper is 0. This means all her kinetic energy has been absorbed by the cord.

The energy absorbed by a spring (a cord can be treated as a spring when it's being stretched) is:

$Ee = \frac{1}{2}*k*\Delta x^{2}$

Where:

Ee = elastic potential energy

k = elastic constant

Δx = lenght the spring was stretched

When a body falls, it's potential gravitational energy is converted to kinetic energy. So the kinetic energy of a body can be calculated as the gravitational potential energy it lost.

The gravitational potential energy is:

$Ep = m * g * \Delta h$

Where:

Ep: potential gravitational energy

m: mass

g: acceleration of gravity

Δh: change of height (final - initial)

When she has fallen 31 m she has lost

62 kg * 9.81 m/s^2 * 31 m = 18854 J

Since her velocity at the bottom is 0, her kinetic energy is 0 J.

All her kinetic energy has been absorbed by the cord and transformed into elastic potential energy. So we can equate these two energies.

Ep = Ee

Then:

$Ep = \frac{1}{2}*k*\Delta x^{2}$

Δx = 31 m - 12 m = 19 m

From here the only unknown is k:

$k = 2 * Ep / (\Delta x ^{2})$

$k = 2 * 18854 J / ((19 m) ^{2}) = 104.5 N/m$

3 0

3 years ago

If a freely falling object were equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s², then i

babymother [125]

Answer:

20 m/s

Explanation:

The acceleration of an object determines the increase in velocity per second.

In this case the acceleration is 20m/s^2.

$a=\frac{v}{t}=\frac{\frac{20m}{s}}{s}$

That is, the increase is 20m/s each second.

I hope this is useful for you

Regards

7 0

4 years ago

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A 2.81 μF capacitor is charged to 1220 V and a 6.61 μF capacitor is charged to 560 V. These capacitors are then disconnected fro

fenix001 [56]

Answer:

756.88 Volts will be the potential difference across each capacitor.

Explanation:

$Q=C\times V$

Q = Charge on capacitor

C = Capacitance

V = Voltage across capacitor

Capacitance of first capacitor = $C_1=2.81 \mu F=2.81\times 10^{-6} F$

Charge of first capacitor = $Q_1$

Voltage across first capacitor = $V_1=1220 V$

$Q_1=C_1V_1$

$Q_1=2.81\times 10^{-6} F\times 1220 V=0.0034282 C$

Capacitance of first capacitor = $C_2=6.61\mu F=6.61\times 10^{-6} F$

Charge of second capacitor = $Q_2$

Voltage across first capacitor = $V_2=560 V$

$Q_2=C_2V_2$

$Q_1=6.61\times 10^{-6} F\times 560 V=0.0037016 C$

Both the capacitors are disconnected and positive plates are now connected to each other and the negative plates are connected to each other. These capacitors are connected in parallel combination.

Total charge = Q

$Q =Q_1+Q_2=0.0034282 C+ 0.0037016 C=0.0071298 C$

Total capacitance in parallel combination:

$C_p=C_1+C_2=2.81\times 10^{-6} F+6.61\times 10^{-6} F=9.42\times 10^{-6} F$

Potential across both capacitors = V

$V=\frac{Q}{C}=\frac{0.0071298 C}{9.42\times 10^{-6} F}=756.88 V$

756.88 Volts will be the potential difference across each capacitor.

8 0

3 years ago

If the magnets are brought close together, they will

murzikaleks [220]

It depends on which side. Opposites attract, so north and south would attract to each other and collide, while north and north or south and south would go away from eachother.

7 0

4 years ago

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Using a simple machine the simple machine cannot increase the amount of ___,but can increase the amount of ____.

Using a simple machine the simple machine cannot increase the amount of _,but can increase the amount of __.