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3 years ago

When the resistance in a circuit remains constant, how are the voltage and current related?

Physics

2 answers:

ELEN [110]3 years ago

6 0

Answer:

The current doubles when the voltage doubles because they are directly proportional.

Explanation:

When relating resistance (R), current (I), and voltage (V), we use Ohms Law

V = I R

As a simple example, if we plug some random values into the equation we can see this in action

V = 6V

I = 2A

R = 3Ω

6 = 2 * 3

Now if we keep the resistance the same but double the voltage, the current will have to double to show the change

12 = 4 * 3

So, The current doubles when the voltage doubles because they are directly proportional.

AfilCa [17]3 years ago

4 0

Answer: The answer is option a.

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Answer:

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Explanation:

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3 years ago

When two equal forces act on the same object in opposite directions, what is the net force?

sertanlavr [38]

Answer:

Explanation:

Forces with equal magnitudes and opposite directions cancel each other out, so the net force is 0.

6 0

3 years ago

Read 2 more answers

In an emergency situation, firemen need to respond as quickly as possible. If a fireman is responding from the second floor, how

rjkz [21]

Answer:

4m/s

Explanation:

May be different considering how long the pole is and how heavy the firefighter is.

8 0

3 years ago

A radar for tracking aircraft broadcasts a 12 GHz microwave beam from a 2.0-m-diameter circular radar antenna. From a wave persp

NISA [10]

A) 750 m

First of all, let's find the wavelength of the microwave. We have

$f=12GHz=12\cdot 10^9 Hz$ is the frequency

$c=3.0\cdot 10^8 m/s$ is the speed of light

So the wavelength of the beam is

$\lambda=\frac{c}{f}=\frac{3\cdot 10^8 m/s}{12\cdot 10^9 Hz}=0.025 m$

Now we can use the formula of the single-slit diffraction to find the radius of aperture of the beam:

$y=\frac{m\lambda D}{a}$

where

m = 1 since we are interested only in the central fringe

D = 30 km = 30,000 m

a = 2.0 m is the aperture of the antenna (which corresponds to the width of the slit)

Substituting, we find

$y=\frac{(1)(0.025 m)(30000 m)}{2.0 m}=375 m$

and so, the diameter is

$d=2y = 750 m$

B) 0.23 W/m^2

First we calculate the area of the surface of the microwave at a distance of 30 km. Since the diameter of the circle is 750 m, the radius is

$r=\frac{750 m}{2}=375 m$

So the area is

$A=\pi r^2 = \pi (375 m)^2=4.42\cdot 10^5 m^2$

And since the power is

$P=100 kW = 1\cdot 10^5 W$

The average intensity is

$I=\frac{P}{A}=\frac{1\cdot 10^5 W}{4.42\cdot 10^5 m^2}=0.23 W/m^2$

4 0

3 years ago

A lacrosse ball that is thrown straight upwards reaches a maximum height of 4.5 m. At what initial velocity was it thrown? (note

shtirl [24]

Answer:

The initial velocity was 9.39 m/s

Explanation:

Lets explain how to solve the problem

The ball is thrown straight upward with initial velocity u

The ball reaches a maximum height of 4.5 m

At the maximum height velocity v = 0

The acceleration of gravity is -9.8 m/s²

We need to find the initial velocity

The best rule to find the initial velocity is v² = u² + 2ah, where v is

the final velocity, u is the initial velocity, a is the acceleration of

gravity and h is the height

⇒ v = 0 , h = 4.5 m , a = -9.8 m/s²

⇒ 0 = u² + 2(-9.8)(4.5)

⇒ 0 = u² - 88.2

Add 88.2 to both sides

⇒ 88.2 = u²

Take square root for both sides

⇒ u = 9.39 m/s

The initial velocity was 9.39 m/s

5 0

3 years ago