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4 years ago

An ac generator with peak voltage 100 volts is placed across a 10-? resistor. What is the average power dissipated?

1 answer:

3 0

The correct answer is: Average Power = 500 W

Explanation:
Root-mean square voltage = Vrms = Vpeak /√2 = 100 / √2 volts
Resistance = R = 10 Ω
Average power = Pavg = (Vrms)^2<span> / R </span>= (100 * 100) / (2 * 10) = <span>500 W</span>

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A plane flies along a straight line path after taking off, and it ends up 210 km farther east and 90.0 km farther north, relativ

Lapatulllka [165]

<span>A plane flies along a straight line path after taking off, and it ends up 210 km farther east and 90.0 km farther north, relative to where it started. we should use Pythagoras theorem for this. distance^2= 210^2 + 90^2.=228.47km, when rounding off this would comes around 230 km</span>

8 0

3 years ago

Read 2 more answers

g As observed on earth, a certain type of bacteria is known to double in number every 24 hours. Two cultures of these bacteria a

tangare [24]

Answer:

86.4 hrs

Explanation:

The amount of bacteria is initially 1

It doubles every 24 hrs.

After first 24 hrs, the amount = 2

After next 24 hrs = 4

After next 24 hrs = 8

After next 24 hrs = 16

After next 24 hrs = 32

After next 24 hrs = 64

After next 24 hrs = 128

After next 24 hrs = 256

Total time taken to reach 256 = 24 x 8 = 192 hrs

For the bacteria culture on the rocket that travels at a speed of 0.893c relative to the earth, this time is contracted by the relationship

t = t'(1 - ¥^2)^0.5

Where t is the contracted time =?

t' is the time on earth

¥ = v/c

Where v is the speed of the rocket

c is the speed of light

since v = 0.893c

¥ = 0.893

Substituting, we have

t = 192 x (1 - 0.893^2)^0.5

t = 192 x 0.2025^0.5

t = 192 x 0.45 = 86.4 hrs

8 0

3 years ago

When 30 V is applied across a resistor it generates 600 W of heat: what is the magnitude of its resistance?

grandymaker [24]

Answer:

Explanation:

Power is expressed as P = V²/R

R = resistance

V = supplied voltage

Given P = 600W and V = 30V

R = V²/P

R = 30²/600

R = 900/600

R = 1.5ohms

magnitude of its resistance is 1.5ohms

3 0

3 years ago

One end of a string is fixed. An object attached to the other end moves on a horizontal plane with uniform circular motion of ra

sveticcg [70]

Answer:

If both the radius and frequency are doubled, then the tension is increased 8 times.

Explanation:

The radial acceleration ( $a_{r}$ ), measured in meters per square second, experimented by the moving end of the string is determined by the following kinematic formula:

$a_{r} = 4\pi^{2}\cdot f^{2}\cdot R$ (1)

Where:

$f$ - Frequency, measured in hertz.

$R$ - Radius of rotation, measured in meters.

From Second Newton's Law, the centripetal acceleration is due to the existence of tension ( $T$ ), measured in newtons, through the string, then we derive the following model:

$\Sigma F = T = m\cdot a_{r}$ (2)

Where $m$ is the mass of the object, measured in kilograms.

By applying (1) in (2), we have the following formula:

$T = 4\pi^{2}\cdot m\cdot f^{2}\cdot R$ (3)

From where we conclude that tension is directly proportional to the radius and the square of frequency. Then, if radius and frequency are doubled, then the ratio between tensions is:

$\frac{T_{2}}{T_{1}} = \left(\frac{f_{2}}{f_{1}} \right)^{2}\cdot \left(\frac{R_{2}}{R_{1}} \right)$ (4)

$\frac{T_{2}}{T_{1}} = 4\cdot 2$

$\frac{T_{2}}{T_{1}} = 8$

If both the radius and frequency are doubled, then the tension is increased 8 times.

5 0

3 years ago

You throw a tennis ball straight up (neglect air resistance). It takes 7.0 seconds to go up and then return to your hand. How fa

sattari [20]

Answer:

Velocity of throwing = 34.335 m/s

Explanation:

Time taken by the tennis ball to reach maximum height, t = 0.5 x 7 = 3.5 seconds.

Let the initial velocity be u, we have acceleration due to gravity, a = -9.81 m/s² and final velocity = 0 m/s

Equation of motion result we have v = u + at

Substituting

0 = u - 9.81 x 3.5

u = 34.335 m/s

Velocity of throwing = 34.335 m/s

6 0

4 years ago