Define 1 kg of mass as international standard​

Answer:

a) Wood is positively charged when rubbed with wool.

b) Wood is positively charged when rubbed with silk.

c) Wood is negatively charged when rubbed against ivory.

a) A madeira é carregada positivamente quando esfregada com lã.

b) A madeira é carregada positivamente quando esfregada com seda.

c) A madeira é carregada negativamente quando esfregada contra o marfim.

Explanation:

English Translation

According to the sequence of substances listed in the table opposite, if we rub glass with wool it will be positively charged. what will be the charge of the wood when rubbed with a) wool? b) silk? c) ivory?

Solution

What will happen when two materials are rubbed on each other is due to the sequence on the static electricity table, with the materials arranged based on their tendencies to rub off electrons from one another.

Materials lower on the table can rub off electrons from materials higher on the table, thereby making the higher material positively charged.

a) Wood and Wool

Wood is higher than wool on this table, hence, wool easily rubs off electrons from the surface of the wood and leaves the wood with an overall more positive charges. Wood is positively charged after this.

b) Wood and Silk

Wood is higher than silk on this table, hence, silk easily rubs off electrons from the surface of the wood and leaves the wood with an overall more positive charges. Wood is positively charged after this.

c) Wood and Ivory

Wood is lower than ivory on this table, Hence, wood rubs off electrons from the surface of the ivory material and the overall charges on the wood is more negative. Wood is negatively charged after this.

In Portugese/Em português

O que acontecerá quando dois materiais forem esfregados um no outro é devido à sequência na tabela de eletricidade estática, com os materiais organizados com base em suas tendências de esfregar elétrons um do outro.

Os materiais mais baixos da mesa podem remover elétrons dos materiais mais altos da mesa, tornando o material mais alto carregado positivamente.

a) Madeira e lã

A madeira é mais alta que a lã nesta tabela; portanto, a lã retira facilmente elétrons da superfície da madeira e deixa a madeira com uma carga geral mais positiva. A madeira é carregada positivamente depois disso.

b) Madeira e seda

A madeira é mais alta que a seda nesta tabela; portanto, a seda retira facilmente elétrons da superfície da madeira e deixa a madeira com uma carga geral mais positiva. A madeira é carregada positivamente depois disso.

c) Madeira e Marfim A madeira é mais baixa que o marfim nesta tabela. Portanto, a madeira elimina elétrons da superfície do material de marfim e as cargas gerais na madeira são mais negativas. A madeira é carregada negativamente depois disso.

Hope this Helps!!!

Espero que isto ajude!!!

Answer:

[tex]v'=v_2-v_1=5\frac{km}{h}[/tex]

Explanation:

The relative speed between the trains is given by:

[tex]v'=v_2-v_1[/tex]

v1: speed of the first train

v2: speed of the second train

To find the relative velocity you write the equation of motion of both train by taking into account the information of the statement. The trains have constant velocity. Furthermore, the second train stars 10 km behind the other one. hence you have:

[tex]x=10+v_1t\\\\x=v_2t[/tex]

for t = 2 hours, the positions of both trains are equal, thus you have:

[tex]10+v_1t=v_2t[/tex]

you factor v2 - v1 from the last equation and replace t = 2h:

[tex]10=v_2t-v_1t\\\\10=(v_2-v_1)t\\\\v_2-v_1=\frac{10}{t}=\frac{10}{2}=5 \frac{km}{h}[/tex]

Hence, you have that the relative velocity is:

[tex]v'=v_2-v_1=5\frac{km}{h}[/tex]

Explanation:

Moving mass m = 4.0Kg

Momentum P = 20.0Kgm/s

Speed V = ?

Momentum = product of mass and its velocity

P = mV

V = P

m

V = 20

4

V = 5m/s

The ball's speed is 5 m/s.

Speed is distance travelled by the object per unit time. Due to having no direction and only having magnitude, speed is a scalar quantity With SI unit meter/second.

Given parameters:

Mass of the ball; m = 4.0Kg

Momentum of the ball; P = 20.0Kgm/s

We have to find; the speed of the ball; v = ?

We know that: Momentum of the ball = product of mass and its speed

⇒ P = mv

⇒ v = P/m

⇒ v = 20.0/4.0 m/s.

⇒ v = 5m/s

Hence, the speed of the ball is 5 m/s.

Learn more about speed here:

https://brainly.com/question/28224010

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Answer:

[tex]\vec{B}_{y}=6T[/tex]

Explanation:

Here we can use the Lorentz force equation.

[tex]\vec{F}_{B}=q(\vec{v}\times \vec{B})[/tex]

We know:

So we will have:

[tex] (0.4i-20j+12k)=2((2.0i+4.0j+6.0k) \times (ai+bj+ck))[/tex]  

Let's solve the cross product, knowing that x component of B is 0, it means a=0.

[tex] (0.4i-20j+12k)=2((2.0i+4.0j+6.0k) \times (0i+bj+ck))[/tex]  

[tex] (0.4i-20j+12k)=2((4c-6b)i-2cj+2bk)[/tex]  

Comparing the k component we have:

[tex]12=2b [/tex]

[tex]b=6 [/tex]            

If we see b is the y-component of the magnetic field, therefore [tex]\vec{B}_{y}=6T[/tex]

I hope it helps you!

-0.033 units

According to Lorentz force law, the magnetic force, F, on a moving charge, q, moving with a velocity, v, in a magnetic field, B, is given by;

F = q v x B   ----------------(i)

Where;

F, v and B are vectors. Therefore, equation (i) represents a vector product of the velocity and magnetic field vectors.

From the question;

v = (2.0i + 4.0j + 6.0k)m/s

F = (0.4i - 20j + 12k)N

q = 2.0C

Let the magnetic field vector be given by;

B = ai + bj + ck               ---------------------(*)

Where;

a, b and c are the magnitudes of the x, y and z components of the magnetic field.

Substitute the values of F, v, B and q into equation (i) as follows;

(0.4i - 20j + 12k) = 2.0(2.0i + 4.0j + 6.0k) x (ai + bj + ck)

Expanding the second bracket gives

(0.4i - 20j + 12k) = (4.0i + 8.0j + 12.0k) x (ai + bj + ck)          ---------------(ii)

Solving the right hand side of equation (ii) which is the vector product gives;

                                       |                                       |

                                       |  i               j                 k |

 (0.4i - 20j + 12k) =        |  4.0         8.0         12.0  |

                                      |  a             b                 c  |

                                      |                                        |

(0.4i - 20j + 12k)  = (8.0c - 12.0b)i - (4.0c -12.0a)j + (4.0b - 8.0a)k      ----(iii)

Comparing both sides of equation (iii) gives the following three equations;

0.4 = 8.0a - 12.0b           --------------------(iv)

-20 = 4.0c - 12.0a          ---------------------(v)

12 = 4.0b - 8.0a             ----------------------(vi)

From the question, it is given that the x component of the magnetic field is equal to zero. Now, recall that from equation (*) above, the magnitude of the x-component of the magnetic field is given as a

Therefore;

a = 0

To get the y component, which is b, substitute the value of a = 0 into equation (iv) as follows;

0.4 = 8.0(0) - 12.0b

0.4 = 0 - 12.0b

0.4 = - 12.0b

Solve for b;

b = [tex]\frac{-0.4}{12.0}[/tex] = -0.033

Therefore the y component of the magnetic field is -0.033 units

Answer:

a) Direct

b) Direct

c) Inverse

d) Direct

e) Inverse

Explanation:

a) Speed of Car and Distance Traveled

Direct

Since, speed = (distance)(time)

Therefore, for constant time, Speed α Distance

b) No. of People at Party and Amount of Food Consumed

Direct

Since,

Food Consumed = (Food Consumed by 1 Person)(No. of People at Party)

Therefore, for constant amount of food consumed by 1 person,

Food Consumed α No. of People at Party

c) Elevation above Sea Level and Air Temperature

Inverse

The relation between altitude and air temperature is not constant. It changes in every layer of the atmosphere. So, if we only talk about the first layer, that is, Troposphere. Then the relation between elevation above sea level and air temperature is:

Air Temperature α 1/Elevation Above Sea Level

As, the elevation increases the air temperature decreases.

d) Distance of a Planet from Sun and Period of Revolution

Direct

According to Kepler's Law:

Period of Revolution α (Distance from Sun)^1.5

e) Temperature of a Bowl of Soup and Time

Inverse

Since, the initial temperature of soup is higher than the surrounding. Thus it loses heat to the surrounding with time. As a result the temperature of the soup decreases with time.

Therefore,

Temperature of Bowl of Soup α 1/Time

Answer:

lf you drop an object and it hasn't been able to attain a significant fraction of it's terminal velocity by the time it hits the ground or whatever other event ends your experiment then you can ignore air resistance

Answer:

(See explanation below for further details)

Explanation:

(The following question is written in Spanish and for this purpose the answer will be written in such language).

1) La propagación del calor a través de sólidos, así como líquidos o gases en condiciones estacionarias se denomina conducción.

2) La propagación del calor a través de líquidos o gases en movimiento se denomina convección.

3) La propagación del calor a través del vacío o sin necesidad de un medio material se denomina radiación.

Answer:b

Explanation:

velocity of a falling object increases.

so Kinetic energy of a falling object increases

height of a falling object from the ground decreases.

so the potential energy of a falling object decreases

Answer:

Distance covered by the satellite in 24 hours

s=2πr

  =2×3.14×42250=265464.58 km

Therefore speed of satellite,

v  = [tex]\frac{time taken}{distance travelled}[/tex]

 =  24×60×60 /265464.58 ​  

 =[tex]3.07 km s^{-1}[/tex]  −

Explanation:

v=  time taken /distance travelled

​  

Answer:

a) 12m/s b) 720m

Explanation:

Use SUVAT:

a) u=0 a= 0.1  t= 2mins = 120 seconds v=?

v=u+at

v= 0 +(0.1*120)

v=12m/s

b) s=? u=0 a=0.1 t=120

s=ut+1/2at^2

s=0*120+1/2*0.1*120^2

s=720m

Answer:

Solar energy.

Wind energy.

Hydro energy.

Tidal energy.

Geothermal energy.

Biomass energy.

Answer:

it is used on hard disk drives, speakers, motors, mri machines, and generators

Explanation:

there ya go

Answer:

20.4 cm; 2.4 cm  

Explanation:

The formula for the pressure p exerted by a column of a liquid with density ρ and height h is

p = ρgh

where h = the acceleration due to gravity

If you have two liquids balancing each other in a U-tube

     p₁ = p₂

ρ₁gh₁ = ρ₂gh₂

 ρ₁h₁ = ρ₂h₂

Data:

ρ₁ = 1010 kg/m³; h₁ = 18 cm

ρ₂ = 890 kg/m³; h₂ = ?          

1. Height of oil column

We measure from the horizontal red line.

[tex]\begin{array}{rcl}\rho_{1}h_{1} & = &\rho_{2}h_{2}\\\text{1010 kg/m}^{3} \times \text{18 cm} & = & \text{890 kg/m}^{3} \times h_{2}\\\text{18 180 cm} & = & 890h_{2}\\h_{2} & = & \dfrac{\text{18180 cm}}{890}\\\\ & = & \text{20.4 cm}\\\end{array}\\ \text{The height of the oil column is $\textbf{20.4 cm}$}[/tex]

2. Height of oil above water

h₂ - h₁ = 20.4 cm – 18 cm = 2.4 cm

Answer: this is true

Explanation: another one is if it is disproved

Answer:

4176 J

Explanation:

Ella speed (V) = 12 m/s, Mass = 58 kg.

Kinetic energy of a body is the energy it possesses as a result of its motion. It is the energy (work) needed to cause a given body to move from rest to its final velocity. It is measured in Joules. The kinetic energy of a body is the same until its velocity changes.

Kinetic energy = 1/2 × m × V²

Kinetic energy = 0.5 × 58 × 12² = 4176 J

Explanation:

Kepler’s third law states that for all objects orbiting a given body, the cube of the semimajor axis (A) is proportional to the square of the orbital period (P).

For each of our planets orbiting the Sun, the relationship between the orbital period and semimajor axis can be represented by the equation as:

[tex]P^2=kA^3[/tex]

k is constant of proportionality

It is required to solve the above equation for k

[tex]k=\dfrac{P^2}{A^3}[/tex]

Answer:

k is constant of proportionality

It is required to solve the above equation for k

Explanation:

Answer:

Because they would naturally dye the test strips in the colors violet and red, regardless of their pH values

(would really appreciate the brainliest)

Answer:

they are naturally dark/dying the strips.

Explanation:

Answer:

  d  The energy is transformed to sound and heat energy.

Explanation:

Each time the basketball bounces, it makes sound waves, and dissipates energy in the form of heat in the material of the ball and the surrounding air. There is no light or chemical change involved.

Answer:

Reflection is when light bounces off an object. If the surface is smooth and shiny, like glass, water or polished metal, the light will reflect at the same angle as it hit the surface. This is called specular reflection.

Answer:

1.54 = sin 35/sin r

sin r = 0.57/1.54 =0.37

r = sin^-1( 0.37)

=21.7°

Answer: 7

Explanation:

The pH of water, a neutral substance, is 7. Human tears are a saline composed mostly of water. Therefore, it stands to reason that a tear-free shampoo would have a similar pH close to 7.

Answer:

the pH level would be 7

Explanation:

Answer:

D) the preformence of mucles for long periods of time

Answer:

The gravitational attraction between the two masses is 24.7 N.

Explanation:

We have,

Mass of object 1, [tex]m_1=15\times 10^5\ kg[/tex]            

Mass of object 2, [tex]m_2=20\times 10^6\ kg[/tex]

Distance between masses is 9 m

We know that there exists a gravitational force between masses when they are placed at certain distance. The gravitational force between masses is given by :

[tex]F=G\dfrac{m_1m_2}{r^2}\\\\F=6.67\times 10^{-11}\times \dfrac{15\times 10^5\times 20\times 10^6}{(9)^2}\\\\F=24.7\ N[/tex]

So, the gravitational attraction between the two masses is 24.7 N.

Answer:

B. lower, greater

...............

Answer:

Explanation:

electrons are a waste product of bacteria living around plant roots – plants discharge organic matter into the soil, which is broken down by bacteria. It is possible to harvest them using motonless electrodes and turn them into electricity, without affecting the plant’s growth in any way.

Answer:

An image is formed on the retina with light rays converging most at the cornea and upon entering and exiting the lens. Rays from the top and bottom of the object are traced and produce an inverted real image on the retina. The distance to the object is drawn smaller than scale

Answer:

Explanation:

The question is asked in portuguese

Hence, it will be answered in portuguese

1kg = 1000g

e

1 g = 1000mg

então

1 kg = 1 x (1000 x 1000)

1 kg = 1x 1.000.000

1 kg = 1.000.000mg

assim

 1 comprimido -------------> 0,025 mg

 x  comprimido ------------> 1.000.000 mg   ( só cruzar)

0,025(x) = 1(1.000.000)

0,025x = 1.000.000

x = 1.000.000/0,025

x = 40.000.000

Answer:

It has 5 I hope this helps you