Ask question

Ask question

All categories

4 years ago

8

1) Halving the distance (i.s., decreasing by a factor of two) between two charged objects will cause the electrical force betwee

n them to be ___ the initial force

1 answer:

Vedmedyk [2.9K]4 years ago

7 0

Answer:

Explanation:

For an electric force, F the formula:

F = kQq/r^2

Given:

r2 = 1/2 × r1

F1 × r1 = k

F1 × r1 = F2 × r2

F2 = (F1 × r1^2)/(0.5 × r1)^2

= (F1 × r1^2)/0.25r1^2

= 4 × F1.

You might be interested in

A train whistle is heard at 300 Hz as the train approaches town. The train cuts its speed in half as it nears the station, and t

spin [16.1K]

Answer:

The speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.

Explanation:

We can calculate the speed of the train using the Doppler equation:

$f = f_{0}\frac{v + v_{o}}{v - v_{s}}$

Where:

f₀: is the emitted frequency

f: is the frequency heard by the observer

v: is the speed of the sound = 343 m/s

$v_{o}$ : is the speed of the observer = 0 (it is heard in the town)

$v_{s}$ : is the speed of the source =?

The frequency of the train before slowing down is given by:

$f_{b} = f_{0}\frac{v}{v - v_{s_{b}}}$ (1)

Now, the frequency of the train after slowing down is:

$f_{a} = f_{0}\frac{v}{v - v_{s_{a}}}$ (2)

Dividing equation (1) by (2) we have:

$\frac{f_{b}}{f_{a}} = \frac{f_{0}\frac{v}{v - v_{s_{b}}}}{f_{0}\frac{v}{v - v_{s_{a}}}}$

$\frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - v_{s_{b}}}$ (3)

Also, we know that the speed of the train when it is slowing down is half the initial speed so:

$v_{s_{b}} = 2v_{s_{a}}$ (4)

Now, by entering equation (4) into (3) we have:

$\frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - 2v_{s_{a}}}$

$\frac{300 Hz}{290 Hz} = \frac{343 m/s - v_{s_{a}}}{343 m/s - 2v_{s_{a}}}$

By solving the above equation for $v_{s_{a}}$ we can find the speed of the train after slowing down:

$v_{s_{a}} = 11.06 m/s$

Finally, the speed of the train before slowing down is:

$v_{s_{b}} = 11.06 m/s*2 = 22.12 m/s$

Therefore, the speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.

I hope it helps you!

7 0

3 years ago

Grade 12 math: vectors as forces?

sashaice [31]

Larger tug force = 2*cos20 forward + 2*sin20 to the right (starboard)
<span>Smaller tug force = 1*cos15 forward + 1*sin15 to the left (port) </span>

<span>Resultant force forward = 2*cos20 + 1*cos15 = 2.8453 (4dp) </span>
<span>Resultant force to right = 2*sin20 - 1*sin15 = 0.4252 (4dp) </span>

<span>Angle of resultant force = arctan(0.4252 / 2.8453) = arctan(0.1494) = 8.5 degrees</span>

4 0

3 years ago

Will give brain list plz help

Mademuasel [1]

Answer:

An electric chemical cell is not always needed to have a power circuit. But every other part is.

5 0

3 years ago

Read 2 more answers

An object with more inertia is both harder to _____ and to _______ ...?

Aleks [24]

An object with more inertia is both harder to start and to stop. <span>The heavier (or more mass) of the object - harder to start & stop. For instance, a large rock vs. small rock. Large rock harder to get rolling & harder to stop as compared to smaller rocks. Hope this answers the question.</span>

4 0

3 years ago

Which phrase describes the paleo-Indians of prehistoric Arkansas?

Vlad [161]

The first one is D hunted with stone-tipped spears

The second one is A

Hope this helps

4 0

3 years ago

Read 2 more answers