An electric field is associated with every:___

A child throws a baseball directly upward. What are the signs of the velocity and acceleration of the ball at the very top of th

Anastaziya [24]

Answer:

velocity zero and acceleration negative

Explanation:

According to the directions taken in the vector analysis, the direction which is upwards taken as positive, the direction which is downwards is taken as negative.

The direction which is rightwards taken as positive and the direction which is leftwards taken as negative.

here, ball throws vertically upwards and it attains a maximum height. At maximum height the magnitude of velocity is zero but the acceleration is always acting downwards so it is taken as negative in sign.

3 0

3 years ago

Newton's Law of Gravitation says that the magnitude F of the force exerted by a body of mass m on a body of mass M is F = GmM r2

Nookie1986 [14]

<h2>Answers:</h2>

According to Newton's Law of Gravitation, the Gravity Force is:

$F=\frac{GMm}{{r}^{2}}$ (1)

This expression can also be written as:

$F=GMm{r}^{-2}$ (2)

If we derive this force $F$ respect to the distance $r$ between the two masses:

$\frac{dF}{dr}dFdr=\frac{d}{dr}(GMm{r}^{-2})dr$ (3)

Taking into account $GMm$ are constants:

$\frac{dF}{dr}dFdr=-2GMm{r}^{-3}$ (4)

Or

$\frac{dF}{dr}dFdr=-2\frac{GMm}{{r}^{3}}$ (5)

<h2> (b) dF/dr represents the rate of change of the force with respect to the distance between the bodies. </h2><h2 />

In other words, this means how much does the Gravity Force changes with the distance between the two bodies.

More precisely this change is inversely proportional to the distance elevated to the cubic exponent.

As the distance increases, the Force decreases.

<h2>(c) The minus sign indicates that the bodies are being forced in the negative direction. </h2>

This is because Gravity is an attractive force, as well as, a central conservative force.

This means it does not depend on time, and both bodies are mutually attracted to each other.

In the first answer we already found the decrease rate of the Gravity force respect to the distance, being its unit $N/km$ :

$\frac{dF}{dr}dFdr=-2\frac{GMm}{{r}^{3}}$ (5)

We have a force that decreases with a rate 1 $\frac{dF_{1}}{dr}dFdr=4N/km$ when $r=20000km$ :

$4N/km=-2\frac{GMm}{{(20000km)}^{3}}$ (6)

Isolating $-2GMm$ :

$-2GMm=(4N/km)({(20000km)}^{3})$ (7)

In addition, we have another force that decreases with a rate 2 $\frac{dF_{2}}{dr}dFdr=X$ when $r=10000km$ :

$XN/km=-2\frac{GMm}{{(10000km)}^{3}}$ (8)

Isolating $-2GMm$ :

$-2GMm=X({(10000km)}^{3})$ (9)

Making (7)=(9):

$(4N/km)({(20000km)}^{3})=X({(10000km)}^{3}$ (10)

Then isolating $X$ :

$X=\frac{4N/km)({(20000km)}^{3}}{{(10000km)}^{3}}$

Solving and taking into account the units, we finally have:

$X=-32N/km$ >>>>This is how fast this force changes when $r=10000 km$

7 0

4 years ago

Read 2 more answers

5. Find the volume of the composite space figure to the nearest whole number.

Dmitry [639]

The shape is missing but let's consider it a semi-cylinder attached to the rectangular prism.
Given:
radius = 4.5 mm
<span>Height = 11 mm </span>

<span>Volume of cylinder = (1/2)(pi)(4.5)^2(11) (the shape is divided into half)
V = 349.89 mm cubed
Volume of prism = L x W x H
= 9 x 11 x 6
= 594 mm cubed
Total volume of the composite shape = 111.375 + 594
= 943.89 mm cubed
Rounded answer = 944 mm cubed.</span>

6 0

4 years ago

A train leaves the station at the 0.0m marker traveling with a constant velocity of 45.0 m/s. How many

Lelechka [254]

Answer:

119.88 km/h

Explanation:

1500/45=33.3

use a m/s to km/h calculator

put in 33.3 for m/s and you will get 119.88 km/h.

119.88 km/h.

5 0

4 years ago

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A large, massive object collides with a stationary, smaller object on an ice rink. If the large object transfers all of its mome

Hunter-Best [27]

Answer:

a ut will move faster than the large object was moving initially

5 0

3 years ago

An electric field is associated with every:____.