How much work in N•m is done when a 10.0-N force moves an object 2.5m?

Which of the following are true statements? A. Like charges repel B. Unlike charges repel C. Unlike charges attract or D. Charge

Brums [2.3K]

Answer: The correct answers are (A) and (C).

Explanation:

The expression from electrostatic force is as follows;

$F=\frac{kq_{1}q_{1}}{r^{2} }$

Here, F is the electrostatic force, k is constant, r is the distance between the charges and $q_{1},q_{1}$ are the charges.

The electrostatic force follows inverse square law. It is inversely proportional to the square of the distance between the charges. It is directly proportional to the product of the charges.

Like charges repel each other. There is a force of electrostatic repulsion between the like charges. Unlike charges attract each other. There is a force of electrostatic attraction between unlike charges.

The charges are induced on the neutral object when it is placed nearby the charged object without actually touching it.

Therefore, the true statements from the given options are as follows;

Like charges repel.

Unlike charges attract.

7 0

3 years ago

A 70 kg student is riding on a skateboard at 4m/s. A 60 kg student is also riding a

Fudgin [204]

Answer is C, one student has more mass, therefore more inertia.

6 0

4 years ago

Why do the sun and moon seem to move across the sky each day? the Earth’s rotation the sun’s rotation the moon’s revolution the

egoroff_w [7]

That would be the Earth's rotation. Hope this helps!

7 0

4 years ago

A single conservative force F = (7.0x - 11) N, where x is in meters, acts on a particle moving along an x axis. The potential en

Umnica [9.8K]

Answer:

(a) 34.6429J

(b) -1.57 m

(c) 4.71 m

Explanation:

The derivative of the potential energy with respect to the position is equal to the negative of the force, so:

$-\frac{dU}{dx}=F\\ dU=-Fdx$

Then, if we integer both sides, we get:

∫dU = -∫(7x - 11)dx

$U=\frac{-7}{2}x^{2} + 11x + c$

we know that U is equal to 26 J when x is zero, so:

$U=\frac{-7}{2}x^{2} + 11x + c$

$26=\frac{-7}{2}(0)^{2} + 11(0) + c$

$26=c$

Finally, the equation for the potential energy is:

$U(x)=\frac{-7}{2}x^{2} + 11x + 26$

Therefore, the maximum positive potential energy is the energy when x is equal to 11/7. That is because the equation of U is the equation of a parable, and the vertex in a parable is given by:

$x=\frac{-b}{2a} = \frac{-11}{2(-7/2)} =\frac{11}{7}$

Where b is the number beside x and a is the number beside $x^{2}$ , Then, the value of maximum U is:

$U(11/7)=\frac{-7}{2}(11/7)^{2} + 11(11/7) + 26$

$U(11/7)=34.6429J$

On the other hand, the negative and positive values of x where the potential energy is equal to zero is calculated as:

$U(x)=\frac{-7}{2}x^{2} + 11x + 26$

$0=\frac{-7}{2}x^{2} + 11x + 26$

if we solve this using the quadratic equation, we get:

$x =\frac{-11+\sqrt{11^{2}-4(-7/2)(26)} }{2(-7/2)}=-1.5747$

$x =\frac{-11-\sqrt{11^{2}-4(-7/2)(26)} }{2(-7/2)}=4.7175$

Finally, the negative and positive values of x where the potential energy is equal to zero are -1.5747 and 4.7175 respectively.

3 0

3 years ago

How many stars our thier in the universe

Svet_ta [14]

<h2>About 1 billion trillion stars</h2>

Since the universe is so big, we don't know for sure what the exact number is, but assuming an average of 100 billion stars per galaxy (which is smaller than a universe), we could say that there are 1 billion trillion stars in the observable universe.

8 0

3 years ago