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Tcecarenko [31]

4 years ago

13

When a 4-μf capacitor has a potential drop of 20 v across its plates, how much electric potential energy is stored in this capac

itor?

1 answer:

Genrish500 [490]4 years ago

7 0

Thew energy stored in a capacitor of capacitance $C$ and voltage between the plates $V$ is

$E=\frac{1}{2} CV^2$ .

Substituting numerical value

$E=\frac{1}{2}(4*10^{-6}) (20)^2\\ E=800\; \mu J$

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Fellow student of mathematical bent tells you that the wave function of a traveling wave on a thin rope is y(x,t)= 2.20 mm cos[(

bezimeni [28]

Answer

given,

y(x,t)= 2.20 mm cos[( 7.02 rad/m )x+( 743 rad/s )t]

length of the rope = 1.33 m

mass of the rope = 3.31 g

comparing the given equation from the general wave equation

y(x,t)= A cos[k x+ω t]

A is amplitude

now on comparing

a) Amplitude = 2.20 mm

b) frequency =

$f = \dfrac{\omega}{2\pi}$

$f = \dfrac{743}{2\pi}$

f = 118.25 Hz

c) wavelength

$k= \dfrac{2\pi}{\lambda}$

$\lambda= \dfrac{2\pi}{k}$

$\lambda= \dfrac{2\pi}{7.02}$

$\lambda= 0.895\ m$

d) speed

$v = \dfrac{\omega}{k}$

$v = \dfrac{743}{7.02}$

v = 105.84 m/s

e) direction of the motion will be in negative x-direction

f) tension

$T = \dfrac{v^2\ m}{L}$

$T = \dfrac{(105.84)^2\times 3.31 \times 10^{-3}}{1.33}$

T = 27.87 N

g) Power transmitted by the wave

$P = \dfrac{1}{2}m\ v \omega^2\ A^2$

$P = \dfrac{1}{2}\times 0.00331\times 105.84\times 743^2\ 0.0022^2$

P = 0.438 W

5 0

3 years ago

How fast did Newton decide a cannon ball shot out in order to escape Earth’s gravity?

arsen [322]

Plugging in for the Earth's mass and for G, we have 11.2 km/s for the escape velocity for an object launched from the Earth's surface. This is about 25,000 miles per hour

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A team of engineers is working with a wind turbine. The team is working with a model and testing different angles for the blade

Zinaida [17]

Answer:

i think it would be which angle converts the most potential energy to into kinetic energy of the turbine

Explanation: because the windmill makes kinetic energy and converts it into mechanical power. then a generator takes the mechanical power and makes it into electricity

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3 years ago

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A spinning ice skater will slow down if she extends her arms away from her body. Which of the following statements explains this

klasskru [66]

Drag from her armas would slow her down if she was spinning at a fast speed

6 0

3 years ago

A boy sledding down a hill accelerates at 1.40 m/s². If

mrs_skeptik [129]

Answer: He would reach 7m/s at the distance of 17,5m.

Explanation: In order for us to know how long it takes for the speed to be reached, we use the equation V= Vo + at, with V=7m/s, Vo= 0m/s since you start from rest and a=1.4m/s². T is the time in seconds that we want to find out.

7 = 0 + 1.4t

7 = 1.4t

t= 5s

Now, we want to know the distance this boy reaches in 5 seconds, in a 7m/s speed and accelarating in 1.4m/s². For finding this out, we use another equation, S = So + Vot + (at²)/2, S being the final distance, So = 0m because he started from rest, and the other variables used before.

S = 0 + 0*5 + [1.4*(5²)]/2

S = 0 + 0 + (1.4*25)/2

S = 35/2

S = 17,5m

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3 years ago