Under what circumstances can air resistance exercises ignored?
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
Tear–free shampoos are advertised as having a pH similar to that of human tears. What pH would you expect tear–free shampoos to be?
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:
A 2.0 c charge moves with a velocity of (2.0i+4.0j+6.0k)m/s and experiences a magnatic force of (0.4i-20j+12k)N. The x component of the magnatic field is equal to zero. Determine the y component of the magnatic field
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:
v is the velocity (2.0i+4.0j+6.0k) m/sF is the magnetic force (0.4i-20j+12k) NB is the magnetic force (ai+bj+ck) Tq is the charge 2 CSo 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
Explanation:
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
A mass of 15 X 10^5 kg is held at a position 9 m away from a mass of 20 X 10^6 kg. What is the gravitational attraction between the two masses?
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.
what is physical fitness? 1) the improvement of the body through inteninoal movement 2) the speed at which the body moves during exersize 3) the ability of the body to function of the body to function efficiently during exercise D) the preformence of mucles for long periods of time
Answer:
D) the preformence of mucles for long periods of time
A bus starting from rest moves with a uniform acceleration of 0.1m/s2 for 2 minutes. Find (a)the speed acquired (b) the 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
write a sentence to describe how an image is formed on retina
when looking at distant objects.
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
Why is friction a problem in space travellers
An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth
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
In laboratorio, versi in un tubo a U acqua da una estremità e olio dall'altra. Le densità dell'olio e dell'acqua sono, rispettivamente, 890 kg/m^3 e 1010 kg/m^3. L'altezza della colonna d'acqua è 18 cm. ▶ A che altezza arriva l'olio nell'altro ramo del tubo? ▶ Quanto vale la differenza fra i livelli superiori dell'acqua e dell'olio nei due rami?
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
In a parallel circuit that has the same number and type of resistors as a series circuit the total resistance will be __________ and the total current will be ________. A.greater;greater B.lower;greater C.greater;the same D.the same;lower
Answer:
B. lower, greater
...............
De acordo com a sequência de substâncias listada na tabela ao lado, se atritarmos vidro com lã, o vidro ficará carregado positivamente. Qual será a carga da madeira quando atritada com: a) lã b) seda c) marfim
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!!!
Astronomers are comparing two stars that are known to have the
same luminosity. Star A is observed to be 4 times brighter than star B.
How far away is Star A compared to Star B?
2 times closer
4 times closer
2 times farther
16 times closer
How man significant figures does the following value gave 43.023
Answer:
It has 5 I hope this helps you
Identify each relationship as direct or inverse by choosing the correct answer from the drop-down menu.
speed of a car and the distance traveled
number of people at a party and the amount of food consumed
elevation above sea level and the air temperature
distance a planet is from the sun and the period of revolution
temperature of a bowl of soup and time
Intro
Done
ODODDDDDDD
5 of 9
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
A 4.0-kg ball has a momentum of 20.0 kg-m/s. What is the ball's speed?
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.
What is speed?
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
#SPJ2
How do power plants generate electricity?
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.
Ella jogs down the street with a speed of 12 m/s. What is her kinetic energy if her mass is 58 kg?
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
5 renewable energy resources
i have nuclear, solar, wind
what am i missin?
Answer:
Solar energy.
Wind energy.
Hydro energy.
Tidal energy.
Geothermal energy.
Biomass energy.
How is 'one standard kilogram' defined in SI system?
Explanation:
The standard one kilogram mass is the mass of platinum-iridium cylinder kept at 0 degree Celsius at the International Bureau of Weights and Measures in France. The mass is equal to mass of 1 litre of water at 4 degree Celsius.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 P2 = kA3, where k is a constant value for all the planets. Rewrite this equation so that it solves for the constant of proportionality, k.
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:
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Answer:
Yoyoyoyoyooyoyy
Explanation:
Yoyoyoyoyoyoyoyoyooy
Answer:
yoyoyoyoyoyooyoyoyoyoyyoyoy
What does an electromagnet do?
Name five (5) things.
Answer:
it is used on hard disk drives, speakers, motors, mri machines, and generators
Explanation:
there ya go
Light is travelling through air reaches quartz at an angle of incidence of 35°. The index of refraction of quartz is 1.54. At what angle of refraction does the light travel into the quartz?
Answer:
1.54 = sin 35/sin r
sin r = 0.57/1.54 =0.37
r = sin^-1( 0.37)
=21.7°
of the ball is
As the object falls off the roof of a tall building_______
turning into______
A) chemical potential energy; gravitational potential energy .
B) gravitational energy; kinetic energy .
C) chemical potential energy; kinetic energy.
D) kinetic energy ;gravitational potential energy.
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
All of the following are ways that an electromagnetic can be made stronger EXCEPT-
A) increasing the size of the iron core
B) adding more loops of wire
C) increasing the current moving through the wire
D) changing the direction of the current moving through the wire
Answer:
D is right option
...............
indica el mecanismo de propagacion del calor en un liquido , gas , solido , vacio
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.
the work done by a force acting through a distance.
Answer:
When a force acts on an object over a distance, it is said to have done work on the object. Physically, the work done on an object is the change in kinetic energy that that object experiences.
Explanation:
google lol
Answer:
When a force acts on an object over a distance, it is said to have done work on the object. Physically, the work done on an object is the change in kinetic energy that that object experiences.
Explanation:
PLZZZZ give me brainliest!!!
Which statement about energy conservation BEST explains why a bouncing basketball will not remain in motion forever?
a The energy is used up and destroyed.
b The energy is transferred to light and potential energy.
c The energy is transformed to heat and chemical energy.
d The energy is transformed to sound and heat energy.
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.
how light recats with each of diffrent types of space and materials
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.