What is the correct definition for friction?

Compare how magnetic forces act through non-magnetic materials and<br>magnetic materials:

gavmur [86]

<h2>Compare how magnetic forces act through non-magnetic materials and </h2><h2>magnetic materials:</h2>

Explanation:

Magnet

• Magnet :- is an object which attracts pieces of iron, steel etc towards itself.

Some facts about magnets:-

• When magnet is freely suspended it always align towards north-south direction

• Like poles always repel & opp. poles attract each other.

• Magnet always exist as dipole

• Two poles can never be separated : if we try to cut it then still both the poles will exist even ina small piece of magnet .it automatically develops the lost polarity

Magnet always develop certain area around it where its effect can be felt ie. magnetic field.

MAGNETIC Field

is studied by drawing imaginary lines called magnetic lines of forces.

Characteristics.

• They always originate from North pole & terminate at South pole. This shows that if north pole was free is move it would have mvre towards south pole.

•Place where they are closer indicate strong M. field i.e. at poles.

•Mag. Field lines gives the direction of magnetic force.

•Two magnetic lines will never intersect each other as they give direction of force & force can’t have 2 direction at a time.

M Field lines are closed continuous curves.

This is what that happens in magnetic materials .

Non magnetic materials

Magnetic forces 'act through' non-magnetic materials
These magnetic materials can be used as a shield around a magnet.
The domain theory of magnetism tries to explain why metals get magnetised
. The magnetic elements have little molecular magnets inside them.
Magnets attract only the magnetic materials

Types of magnetic materials

Soft magnetic materials (e.g. iron) have domains that easily move into line when the metal is placed in a magnetic field but as soon as the field is removed the domains take on a random pattern again. It returns to being unmagnetized straight away.

Hard magnetic materials (e.g. steel) have domains that do not easily move into line when the metal is placed in a magnetic field, a strong field is needed for some time, but then, when the field is removed the domains retain the magnetic pattern. The metal stays magnetic for a long time.

5 0

3 years ago

A projectile of mass 2.0 kg is fired in the air at an angle of 40.0 ° to the horizon at a speed of 50.0 m/s. At the highest poin

tekilochka [14]

Answer:

a) The fragment speeds of 0.3 kg is 33.3 m / s on the y axis

0.7 kg is 109.4 ms on the x axis

b) Y = 109.3 m

Explanation:

This is a moment and projectile launch exercise.

a) Let's start by finding the initial velocity of the projectile

sin 40 = voy / v₀

$v_{oy}$ = v₀ sin 40

$v_{oy}$ = 50.0 sin40

$v_{oy}$ = 32.14 m / s

cos 40 = v₀ₓ / V₀

v₀ₓ = v₀ cos 40

v₀ₓ = 50.0 cos 40

v₀ₓ = 38.3 m / s

Let us define the system as the projectile formed t all fragments, for this system the moment is conserved in each axis

Let's write the amounts

Initial mass of the projectile M = 2.0 kg

Fragment mass 1 m₁ = 1.0 kg and its velocity is vₓ = 0 and $v_{y}$ = -10.0 m / s

Fragment mass 2 m₂ = 0.7 kg moves in the x direction

Fragment mass 3 m₃ = 0.3 kg moves up (y axis)

Moment before the break

X axis

p₀ₓ = m v₀ₓ

Y Axis y

$p_{oy}$ = 0

After the break

X axis

$p_{fx}$ = m₂ v₂

Axis y

$p_{fy}$ = m₁ v₁ + m₃ v₃

Let's write the conservation of the moment and calculate

Y Axis

0 = m₁ v₁ + m₃ v₃

Let's clear the speed of fragment 3

v₃ = - m₁ v₁ / m₃

v₃ = - (-10) 1 / 0.3

v₃ = 33.3 m / s

X axis

M v₀ₓ = m₂ v₂

v₂ = v₀ₓ M / m₂

v₂ = 38.3 2 / 0.7

v₂ = 109.4 m / s

The fragment speeds of 0.3 kg is 33.3 m / s on the y axis

0.7 kg is 109.4 ms on the x axis

b) The speed of the fragment is 33.3 m / s and has a starting height of where the fragmentation occurred, let's calculate with kinematics

$v_{fy}$ ² = $v_{oy}$ ² - 2 gy

0 = $v_{oy}$ ²-2gy

y = $v_{oy}$ ² / 2g

y = 32.14² / 2 9.8

y = 52.7 m

This is the height where the break occurs, which is the initial height for body movement of 0.3 kg

$v_{f}$ ² = $v_{y}$ ² - 2 g y₂

0 = $v_{y}$ ² - 2 g y₂

y₂ = $v_{y}$ ² / 2g

y₂ = 33.3²/2 9.8

y₂ = 56.58 m

Total body height is

Y = y + y₂

Y = 52.7 + 56.58

Y = 109.3 m

8 0

3 years ago

The relative density of oxygen and carbon dioxide are 16, 12 respectively. If 25cm3 of carbon dioxide effuse out in 75 sec what

Mrac [35]

Answer:

32 cm³

Explanation:

The given gas data are;

The relative density of oxygen = 16

The relative density of carbon dioxide = 12

The time it takes 25 cm³ of carbon dioxide to effuse out = 75 seconds'

The duration of effusion of the oxygen = 96 seconds

The rate of effusion of carbon dioxide, R1 = 25 cm³/(75 sec) = (1/3) cm³/sec

According to Graham's law of diffusion and effusion of a gas, we have;

$\dfrac{Rate \ of \ effudion \ of \ gas \ 1}{Rate \ of \ effudion \ of \ gas \ 2} =\dfrac{The \ relative \ density \ of \ gas \ 2}{The \ relative \ density \ of \ gas \ 1}$

Therefore, we have;

$\dfrac{Rate \ of \ effudion \ of \ oxygen}{(1/3)} =\dfrac{12}{16}$

$The \ rate \ of \ effudion \ of \ oxygen}=\dfrac{12}{16} \times \left(\dfrac{1}{3 } \ cm^3/sec\right ) = \dfrac{1}{4} \ cm^3/sec$

The volume of effusion = The rate of effusion × Time

The volume of the oxygen that will effuse in 96 seconds is given as follows;

The rate of effusion of a gas × Time

V = The rate of effusion of oxygen × Time = (1/3) cm³/sec × 96 sec = 32 cm³

The volume of oxygen that will effuse in 96 seconds, V = 32 cm³.

8 0

3 years ago

. Egbert is in a rowboat four miles from the nearest point on Egbert a straight shoreline. He wishes to reach a house 12 miles f

swat32

Answer:

$t=\frac{13}{3} =4.33\ mi.hr^{-1}$

Explanation:

Given:

Distance from the shore, $s=4\ mi$

distance of house from the shore, $h=12\ mi$

speed of rowing, $v_r=3\ mi.hr^{-1}$

speed of walking, $v_w=4\ mi.hr^{-1}$

<em>For the least amount of time to reach the house one must row at the nearest point on the shore and then walk from there.</em>

<u>Now the time taken to reach the shore:</u>

$t_s=\frac{s}{v_s}$

$t_s=\frac{4}{3}\ mi.hr^{-1}$

<u>Time taken in walking to house from the shore:</u>

$t_h=\frac{h}{v_w}$

$t_h=\frac{12}{4}$

$t_h=3\ mi.hr^{-1}$

<u>Therefore total time taken:</u>

$t=t_h+t_s$

$t=\frac{13}{3} =4.33\ mi.hr^{-1}$

6 0

3 years ago

Which is a characteristic of nuclear funsion?

disa [49]

Nuclear fusion is where two Nucluir collide and form a new atom and release a tremendous amount of energy it requires a high activation energy and we cant use it for an energy source as its to dangerous

hope that helps

5 0

4 years ago