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4 years ago

لماذا يتعذر احيانا سير الاشخاص على سطح حليدي افقي

Physics

1 answer:

Sergio [31]4 years ago

5 0

حسنا ، قد يكون أحد الأمثلة على ذلك أن السطح مبلل أو جليدي ، لذلك لا يوجد احتكاك كافٍ للمشي.

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A charge Q is transferred from an initially uncharged plastic ball to an identical ball 24 cm away.The force of attraction is th

xxMikexx [17]

Answer:

The number of electrons transferred from one ball to the other is 2.06 x 10¹² electrons

Explanation:

Given;

magnitude of the attractive force, F = 17 mN = 0.017 N

distance between the two objects, r = 24 cm = 0.24 m

The attractive force is given by Coulomb's law;

$F = \frac{1}{4\pi \epsilon _0} \times \frac{Q^2}{r^2} = \frac{kQ^2}{r^2} \\\\Q^2 = \frac{Fr^2}{k} \\\\Q = \sqrt{ \frac{Fr^2}{k}} \\\\Q = \sqrt{ \frac{(0.017)(0.24)^2}{9\times 10^9}} \\\\Q = 3.298 \times 10^{-7} \ C$

The charge of 1 electron = 1.602 x 10⁻¹⁹ C

n(1.602 x 10⁻¹⁹ C) = 3.298 x 10⁻⁷

$n = \frac{3.298 \times 10^{-7}}{1.602 \times 10^{-19}} = 2.06 \times 10^{12} \ electrons$

Therefore, the number of electrons transferred from one ball to the other is 2.06 x 10¹² electrons

4 0

3 years ago

Lithium sodium potassium rubidium cesium and francium are the same column. Why are these elements in the same column in the peri

tamaranim1 [39]

They have the same number of electrons in their outermost shell

Explanation:

Lithium, sodium, potassium, rubidium, cesium and francium are in the same column on the periodic table because they have the same number of electrons in their outermost shell.

The periodic table is based on the precepts of the modern periodic law which states that "the properties of elements are a periodic function of their atomic number".
In the table elements having the same number of electrons in the outermost shell of their atoms are placed over one another in vertical columns.
Each of the resulting vertical column is known as a group or family.
The given elements belongs to the first family on the periodic table.
In this group, all the elements have just one electron in their outermost shell.

learn more:

Periodic table brainly.com/question/5090516

#learnwithBrainly

4 0

3 years ago

Which statement is

ELEN [110]

Answer:

Explanation: This is the correct answer

8 0

3 years ago

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Calculate the Reynolds number for an oil gusher that shoots crude oil 25.0 m into the air through a pipe with a 0.100-m diameter

Alenkasestr [34]

Answer:

$Re=1992.24$

Explanation:

Given:

vertical height of oil coming out of pipe, $h=25\ m$

diameter of pipe, $d=0.1\ m$

length of pipe, $l=50\ m$

density of oil, $\rho = 900\ kg.m^{-3}$

viscosity of oil, $\mu=1\ Pa.s$

Now, since the oil is being shot verically upwards it will have some initial velocity and will have zero final velocity at the top.

<u>Using the equation of motion:</u>

$v^2=u^2-2gh$

where:

v = final velocity

u = initial velocity

Putting the respective values:

$0^2=u^2-2\times 9.8\times 25$

$u=22.136\ m.s^{-1}$

<u>For Reynold's no. we have the relation as:</u>

$Re=\frac{\rho.u.d}{\mu}$

$Re=\frac{900\times 22.136\times 0.1}{1}$

$Re=1992.24$

6 0

3 years ago

How do tou find the acceleration of a car between two points on a velocity-time variation graph

Bezzdna [24]

The magnitude of acceleration is

(change in speed) divided by (time for the change) .

Between the two points on the graph ...

-- Find the change in speed. (usually the y-axis)
-- Find the change in time. (usually the x-axis)

Divide (change in time) by (change in speed) between the two points.
That quotient is the average magnitude of acceleration during that time.

If the graph happens to be a straight line, then the magnitude of acceleration
is just the slope of the line.

3 0

4 years ago

Read 2 more answers