A block weighing 30kg is moved at a constant speed over a horizontal surface by a force of 100 N applied parallel

When calculating the net electrostatic force, a negative value indicates that the two charged objects involved __________.

DiKsa [7]

Answer:

B

Explanation:

The correct answer is B) have unlike charges. Since they are attracted to each other they have to be unlike

5 0

3 years ago

The inner and outer surfaces of a cell membrane carry a negative and positive charge, respectively. Because of these charges, a

BlackZzzverrR [31]

Answer:

E = 8.5 * 10^6 V/m

Explanation:

In general we have the following relation between the Electric Field and the Elecric Potential:

$\int\limits^2_1 {\vec{E} \cdot\vec{dl}} = V_{2} -V_{1}$

Due to the vector nature of the electric filed, we can only know the mean Electric field E across the membrane, and take it out from the integral, that is:

E = (ΔV)/L

Where L is the thickness of the membrane and ΔV is the potential difference.

Therefore:

E = 8.53933*10^6 V/m

rounding to the first tenth:

E = 8.5 * 10^6 V/m

3 0

3 years ago

A runaway railroad car, with mass 30x10^4 kg, coasts across a level track at 2.0 m/s when it collides with a spring loaded bumpe

Natalija [7]

Answer:

0.775 m

Explanation:

As the car collides with the bumper, all the kinetic energy of the car (K) is converted into elastic potential energy of the bumper (U):

$U=K\\frac{1}{2}kx^2 = \frac{1}{2}mv^2$

where we have

$k=2\cdot 10^6 N/m$ is the spring constant of the bumper

x is the maximum compression of the bumper

$m=30\cdot 10^4 kg$ is the mass of the car

$v=2.0 m/s$ is the speed of the car

Solving for x, we find the maximum compression of the spring:

$x=\sqrt{\frac{mv^2}{k}}=\sqrt{\frac{(30\cdot 10^4 kg)(2.0 m/s)^2}{2\cdot 10^6 N/m}}=0.775 m$

8 0

3 years ago

Read 2 more answers

When objects are heated they tend to expand because

densk [106]

Hello!
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When objects are heated, their molecules tend to vibrate fast. As they vibrate, the space between each atom increases. This keeps on happening, and the object expands until it has cooled down.
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Hope this helps! :)

5 0

3 years ago

What changes would result in a decrease in the gravitational force between two objects? Check all that apply.

REY [17]

<em>I'm sorry, it says check all that apply, however there are no choices given. You should edit, and add the multiple choice answers.</em>

My Answer:

Well if the masses of two objects were both decreased, it would result in a decrease in the gravitational force. So I guess the two objects masses would need to be decreased.

4 0

3 years ago