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3 years ago

7

When two point charges are a distance dd part, the electric force that each one feels from the other has magnitude F.F . In orde

r to make this force twice as strong, the distance would have to be changed to _____

1 answer:

Harman [31]3 years ago

6 0

Answer:

In order to make this force twice as strong, F' = 2 F, the distance would have to be changed to half i.e. r' = r/2.

Explanation :

The electric force between two point charges is directly proportional to the product of charges and inversely proportional to the square of the distance between charges. It is given by :

$F=\dfrac{kq_1q_2}{r^2}$

r is the separation between charges

$F\propto \dfrac{1}{r^2}$

$r=\sqrt{\dfrac{1}{F}}$

If F'= 2F

$r'=\dfrac{1}{\sqrt{2F} }$

In order to make this force twice as strong, F' = 2 F, the distance would have to be changed to half i.e. $r'=\dfrac{1}{\sqrt{2F} }$ . Hence, this is the required solution.

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What is the volume of a 1.2kg and displaced 1.0g/cm3

Zinaida [17]

Mass = 1.2 kg = 1200 grams.

Volume = mass/density = 1200 cm3.

Hope this helps!

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3 years ago

You are on your balcony and notice some bad squirrels digging in your garden directly below. You start tossing your pistachios a

Rashid [163]

Answer:

0.43 s

Explanation:

We have the following parameters:

Initial velocity, u = 7.4 m/s

Acceleration of gravity, g = 9.8 $m/s^2$

Distance, s = 43 in + 10 ft = 1.092 m + 3.048 m = 4.14 m

Time, t = ?

Using the equation of motion $s=ut +\frac{1}{2}gt^2$ , we have

$4.14 = 7.4t + 0.5\times9.8t^2$

$4.9t^2 + 7.4t - 4.14 =0$

Using the quadratic formula $\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$ where a = 4.9, b = 7.4 and c = - 4.14, and solving for the positive value of t only, we have

$t = 0.43$ s

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3 years ago

What is the average acceleration of a tennis ball that has an initial velocity of 6.0 m/s [E] and a final velocity of 7.3 m/s [W

Marizza181 [45]

Given :

The average acceleration of a tennis ball that has an initial velocity of 6.0 m/s.

and a final velocity of 7.3 m/s.

It is in contact with a tennis racket for 0.094 s

To Find :

The average acceleration of the tennis ball.

Solution :

We know, average acceleration is given by :

$a_{avg}=\dfrac{Final \ velocity-Initial\ velocity}{Time\ Taken}\\\\a_{avg}=\dfrac{7.3-6.0}{0.094}\ m/s^2\\\\a_{avg}=13.83\ m/s^2$

Therefore, average velocity is given by 13.83 m/s².

Hence, this is the required solution.

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2 years ago

A merry-go-round with a rotational inertia of 600 kg m2 and a radius of 3. 0 m is initially at rest. A 20 kg boy approaches the

Margaret [11]

Hi there!

$\boxed{\omega = 0.38 rad/sec}$

We can use the conservation of angular momentum to solve.

$\large\boxed{L_i = L_f}$

Recall the equation for angular momentum:

$L = I\omega$

We can begin by writing out the scenario as a conservation of angular momentum:

$I_m\omega_m + I_b\omega_b = \omega_f(I_m + I_b)$

$I_m$ = moment of inertia of the merry-go-round (kgm²)

$\omega_m$ = angular velocity of merry go round (rad/sec)

$\omega_f$ = final angular velocity of COMBINED objects (rad/sec)

$I_b$ = moment of inertia of boy (kgm²)

$\omega_b$ = angular velocity of the boy (rad/sec)

The only value not explicitly given is the moment of inertia of the boy.

Since he stands along the edge of the merry go round:

$I = MR^2$

We are given that he jumps on the merry-go-round at a speed of 5 m/s. Use the following relation:

$\omega = \frac{v}{r}$

$L_b = MR^2(\frac{v}{R}) = MRv$

Plug in the given values:

$L_b = (20)(3)(5) = 300 kgm^2/s$

Now, we must solve for the boy's moment of inertia:

$I = MR^2\\I = 20(3^2) = 180 kgm^2$

Use the above equation for conservation of momentum:

$600(0) + 300 = \omega_f(180 + 600)\\\\300 = 780\omega_f\\\\\omega = \boxed{0.38 rad/sec}$

8 0

2 years ago

What happens to the work done when a force is doubled and the distance moved remain the same?

san4es73 [151]

Answer:

Work done gets doubled.

Explanation:

The work done by a force is given by :

W = Fd

Where

F is force and d is distance move

If the force is doubled and the distance moved remain the same, it would mean that the work done becomes double of the initial work done.

4 0

2 years ago