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3 years ago

calculate the speed with which an object or mass 20kg hits the ground to its kinetic energy of 490 joules (mention formula)

Physics

1 answer:

notka56 [123]3 years ago

6 0

Answer:

Speed = 7m/s

Explanation:

Kinetic Energy = 1/2*(mv²)

v² = (490*2)/20 = 49

v = √49 = 7m/s

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Is 2/2 1 or 0? please help lol

Komok [63]

Answer:

Explanation:

Hello!

In this case, for such mathematical operations, we can wee that the slash represents a fraction or a division, say 8 ÷ 4 = 2, 6 ÷ 3 = 2, 20 ÷ 4 = 5, etc. In such a way, since the operation 2/2, represents 2 ÷ 2, it is clear that two is once in 2, therefore, the result is:

2 ÷ 2 = 1.

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3 years ago

A uniform, solid cylinder of radius 5.00 cm and mass 3.00 kg starts from rest at the top of an inclined plane that is 2.00 m lon

ch4aika [34]

To solve this problem we will apply the principle of conservation of energy, for which the initial potential and kinetic energy must be equal to the final one. The final kinetic energy will be transformed into rotational and translational energy, so the mathematical expression that approximates this deduction is

KE_i+PE_i = KE_{trans}+KE_{rot} +PE_f

$KE_i = 0$ , since initially cylinder was at rest

$PE_f = 0$ since at the ground potential energy is zero

The mathematical values are,

$mgh = \frac{1}{2} mV^2 + \frac{1}{2}I\omega^2$

Here,

m = mass

g= Gravity

h = Height

V = Velocity

$I = \frac{mr^2}{2}$ moment of Inertia in terms of its mass and radius

$\omega = \frac{V}{r}$ Angular velocity in terms of tangential velocity and its radius

Replacing the values we have that

mgh = \frac{1}{2} mv^2 +\frac{1}{2} (\frac{mr^2}{2})(\frac{v}{r})^2

gh = \frac{v^2}{2}+\frac{v^2}{4}

v = \sqrt{\frac{4gh}{3}}

From trigonometry the vertical height of inclined plane is the length of this plane for $sin\theta$ , then

$h = 2.00*sin 25$

$h = 0.845 m$

Replacing,

$v = \sqrt{\frac{4(9.8)(0.845)}{3}}$

$V = 3.32 m/s$

Therefore the cylinder's speedat the bottom of the ramp is 3.32m/s

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3 years ago

PLEASE HELP ASAP 98 POINTS!!!!!!! ALL I NEED YOU GUYS TO DO IS WRITE A ONE PARAGRAPH REFLECTION ON ECLIPSES AND WRITE IT AS IF Y

makvit [3.9K]

A eclipse starts when one object in space is blocking an observer. Most commonly known as the moon blocking the sun. For us having a visual on eclipses we normally have two eclipses. We have the solar eclipse and the lunar eclipse. These are both very important on the timing and the cycles of the moon. A solar eclipse happens when the moon moves in front of the sun. This will cause a shadow to fall on only a few certain places on earth. Then a lunar eclipse is when the Sun, moon, and earth are perfectly aligned. With the earth being the middle the Sun casts its rays and causes a huge shadow on the moon.

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3 years ago

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The current supplied by a battery in a portable device is typically about 0.151 A. Find the number of electrons passing through

butalik [34]

Answer:

n = 1.7*10²² electrons.

Explanation:

As the current, by definition, is the rate of change of charge, assuming that the current was flowing at a steady rate of .151 A during the 5 hours, we can find the total charge that passed perpendicular to the cross-section of the circuit, as follows:

$I =\frac{\Delta q}{\Delta t} \\ \\ \Delta q = I* \Delta t \\ \\ \Delta t = 5hs*\frac{3600s}{1h} = 18000 s$

⇒ Δq = I * Δt = 0.151 A * 18000 s = 2718 C

As this charge is carried by electrons, we can express this value as the product of the elementary charge e (charge of a single electron) times the number of electrons flowing during that time, as follows:

Δq = n*e

Solving for e:

$n = \frac{\Delta q}{e} =\frac{2718C}{1.6-19C} = 1.7e22 electrons.$

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3 years ago

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Do transistors amplfy a.c or d.c<br>

Gnoma [55]

Explanation:

thet amplify DC, because of the voltage ( small current input signal)

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3 years ago

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