Answer: A plane mirror always forms a virtual image (behind the mirror). The image and object are the same distance from a flat mirror, the image size is the same as the object size, and the image is upright.
Explanation:
Which of the following best describes a solid?
A
matter is made of atoms so tightly packed together that they cannot move around
B
takes the shape and volume of its container
C
has a definite volume, but takes the shape of its container
What are the things being compared in the following argument?
"The United Nations failed to intervene in Bosnia to prevent massive human rights violations and ethnic cleansing. It also failed to act to stop the murders of close to a million innocent people in Rwanda. THe UN will not intervene to stop any widespread slaughter of innocents in Nigeria."
a.
Ethnic cleansing in Nigeria and Bosnia
b.
The slaughter of innocents by the UN
c.
situations in which the United Nations might intervene
d.
Human rights violations in Rwanda and Bosnia
Answer:
C
Explanation:
The thing that is being compared in the given argument is Ethnic cleansing in Bosnia. The correct option is A.
What is Ethnic cleansing?Ethnic cleansing is the systematic removal of ethnic, racial, and religious groups from a given area with the goal of ethnically homogenizing the region.
In this group of resettled Bosnian refugees, ethnic cleansing has resulted in high rates of PTSD and depression, as well as other forms of psychological morbidity.
The long-term consequences of ethnic cleansing as a form of mass psychological trauma have yet to be studied.
Political elites seek to gain and/or consolidate political power by capitalizing on nationalism and the desire to create the domestic "other" in order to foster solidarity among the dominant nationality.
The topic under discussion in this argument is ethnic cleansing in Bosnia.
Thus, the correct option is A.
For more details regarding Ethnic cleansing, visit:
https://brainly.com/question/12766738
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An extraterrestrial creature is standing in front of plane mirror. The height of this creature is H and we know that this creature has eyes positioned h below the top of its head. This creature sees its reflection which fit exactly the mirror, it means, this creature can just see the top of head and the bottom of its feet (or whatever it uses for motion). We can conclude that the top of a mirror is exactly:________
a. H/2 above the ground
b. H above the ground
c. (H-h/2) above the ground
d. (H-h) above the ground
e. We can not guess anything without information about the nature of this creature.
Answer:
c. (H-h/2) above the ground
Explanation:
The mirror must be at least half as tall as the alien, and its base must be located at half of the distance between the alien's eyes and the ground (assuming that the alien doesn't float or levitate).
This question is about the Law of Reflection which states that the angle of reflection = angle of incidence.
I attached an image that can help you understand the concept, although the alien is not included.
What is the magnitude and direction of the magnetic force on the bob at the lowest point in its path, if it has a positive 0.250 μC charge and is released from a height of 30.0 cm above its lowest point? The magnetic field strength is 1.50 T.
Answer:
[tex]F=9.09\times 10^{-7}\ N[/tex]
Explanation:
Given that,
Charge, q = 0.250 μC
It is released from a height of 30 cm or 0.03 m
The magnetic field strength is 1.50 T.
First we find the velocity using the conservation of energy as follows :
[tex]mgh=\dfrac{1}{2}mv^2\\\\v=\sqrt{2gh} \\\\v=\sqrt{2\times 9.8\times 0.3} \\\\v=2.424\ m/s[/tex]
Now, the magnetic force is given by :
[tex]F=qvB\\\\=0.25\times 10^{-6}\times 2.424\times 1.5\\\\=9.09\times 10^{-7}\ N[/tex]
So, the magnetic force is [tex]9.09\times 10^{-7}\ N[/tex]. Since, the bob is at the lowest point, the direction of the magnetic force at the lowest point is upward.
At an accident scene on a level road, investigators measure a car's skid mark to be 98 m long. It was a rainy day and the coefficient of friction was estimated to be 0.38. a) Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes.b) Why does the car's mass not matter?
Answer:
a. V = 19.1m/s
b. The mass of the car does not matter
Explanation:
A.
KE = 1/2mv² = fd --------(1)
Fd = umgd ---------(2)
Therefore,
1/2mv² = umgd ---------(3)
M will cancel itself out from both sides of equation 3.
Then we will have:
1/2v² = ugd
Then we cross multiply to make v² the subject of the formula
V² = 2ugd
V = √2ugd -------(4)
U = 0.38
g = 9.81
d = 98
When we input these values into equation 4, we will have:
V = √2x0.38x9.81x98
V = √730.6488
V = 27.03m/s
B.
The mass of the car does not actually matter as the mass was cancelled out on the both sides of equation 3
A potential difference of 1.20 V will be applied to a 33.0 m length of 18-gauge copper wire (diameter = 0.0400 in.). Calculate (a) the current, (b) the magnitude of the current density, (c) the magnitude of the electric field within the wire, and (d) the rate at which thermal energy will appear in the wire.
Answer:A) Current = 1.739A, B)current density, J = 2.147x10^6 A/m2
magnitude of electric field , E = 0.036 N/C
)rate of thermal energy, P =2.086W
Explanation:
Resistance = R = ρL/A
But the cross-section area of the wire. is given as
Diameter / 2 = 0.04/2 =0.02in to m = 0.02 / 39.37= 0.000508
A = πr^2 = π x 0.000508^2 = 8.10 x 10^-7
since resistivity of copper,ρ= 17x10-9 ohm.m
so resistance is R = ρL/A
17x10-9 x 33 / 8.1x10-7
= 0.69 ohm.
A) Current = I = Voltage /Resistance =1.20/0.69 =1.739A
B)current density, J = Current /Area
= 1.739/8.1x10-7
= 2.147x10^6 A/m2
c)magnitude of electric field , E = Current density x resistivity =J ρ
E = 2.147 x 10^6 x 17 x 10^-9
E = 0.036 N/C
D)rate of thermal energy, P = I² R =1.739² X 0.69
=2.086W
In a warehouse, the workers sometimes slide boxes along the floor to move them. Two boxes were sliding toward each other and crashed. The crash caused both boxes to change speed. Based on the information in the diagram, which statement is correct? In your answer, explain what the forces were like and why the boxes changed speed.
Box 1 has more mass than Box 2.
Box 1 and Box 2 are the same mass.
Box 1 has less mass than Box 2.
**YOU MUST BE DESCRIPTIVE! Any short answers not explaining it wont get brainliest!**
Answer:
box 1 has larger mass than box 2
Explanation:
We need to consider the linear momentum of the boxes immediately before and after they crash.
Recall that momentum is defined as mass times velocity.
So for before the collision, the linear momentum of the system of two boxes is:
m1 * 4km/h - m2 * 8km/h
with m1 representing mass "1" on the left, and m2 representing mass 2 on the right.
Notice the sign of the linear momentum (one positive (moving towards the right) and the other one negative (moving towards the left)
For after the collision, we have or the linear momentum of the system:
- m1 * 2km/h - m2 * 1km/h
Then, since the linear momentum is conserved in the collision, we make the initial momentum equal the final and study the mass relationship between m1 and m2:
4 m1 - 8 m2 = - 2 m1 - m2
combining like terms for each mas on one side and another of the equal sign, we get;
4 m1 + 2 m1 = 8 m2 - m2
6 m1 = 7 m2
therefore m1 = (7/6) m2
which (since 7/6 is a number larger than one) tells us that m1 is larger than m2 by a factor of 7/6
Therefore, answer 1 is the correct answer.
HELP !Which is an example of a destructive force that shapes Earth's surface?
clouds
volcanoos
wind orosion
sodiment deposits
Answer:
wind orosion is the correct answer dkr this
A golfer hits the ball off the tee at an angle of thirty-five degrees from the horizontal with a speed of 46 m/s. It lands on the green, which is elevated 5.50 m higher than the tee. How much time elapsed from when the ball was hit to when it landed on the green?
Answer:
t = 5.16 seconds.
Explanation:
The flight time can be found using the following equation:
[tex] y_{f} = y_{0} +v_{0y}*t - \frac{1}{2}gt^{2} [/tex]
Where:
t: is the time
g: is the gravity = 9.81 m/s²
y₀: is the initial height = 0
[tex]y_{f}[/tex]: is the final height = 5.50 m
[tex]v_{0y}[/tex]: is the initial vertical velocity = v*sin(35)
v: is the speed = 46 m/s
[tex] 5.50 = 46*sin(35)*t - \frac{1}{2}9.81*t^{2} [/tex]
By solving the above cuadratic equation we have:
t₁= 0.22 s and t₂= 5.16 s
We will take the solution equal to 5.16 seconds, since in 0.22 seconds (very short time) the ball is going up and in 5.16 seconds it landed on the green.
Therefore, 5.16 seconds have passed since the ball was hit until it landed.
I hope it helps you!
The image blow shows a certain type of global wind:
What best describes these winds? Polar easterlies caused by air above poles being relatively warmer.
Polar easterlies caused by air above poles being relatively cooler.
Trade winds caused by air above equator being relatively warmer.
Trade winds caused by air above equator being relatively cooler.
Answer:
i got u its a
Explanation:
A radio signal has a frequency of 1.023 x 108 HZ. If the speed of the signal in air is 2.997 x 108m/s, what is the wavelength of the signals? а 7.15 m b 5.23 m C 2.93 m d 0.93 m
Answer:
2.93 m (which agrees with answer "C" on the list)
Explanation:
Recall that the speed of the wave equals the product of the wave's length times its frequency. Therefore, the wavelength is going to be the quotient of the speed of the signal divided its frequency:
Wavelength = 2.997 10^8 / 1.023 10^8 = 2.93 m
What is the Poynting vector S⃗ (x,t)S→(x,t), that is, the power per unit area associated with the electromagnetic wave described in the problem introduction
Answer:
[tex]\mathbf{S^{\to} (x,t) = \dfrac{{E_o} {B_o}}{\mu_o} sin^2 (kx -wt) \hat i }[/tex]
Explanation:
Consider:
[tex]E^{\to} =E_o \ Sin (kx - wt) \hat j[/tex]
[tex]B^{\to} =B_o \ Sin (kx - wt) \hat k[/tex]
The equation for the Poynting vector is given as:
[tex]S^{\to} (x,t) = \dfrac{E^{\to}\times B^{\to}}{\mu_o}[/tex]
[tex]S^{\to} (x,t) = \dfrac{E_o \ Sin(kx - wt) \hat j \times B_o sin (kx -wt) \hat k}{\mu_o}[/tex]
[tex]S^{\to} (x,t) = \dfrac{{E_o} {B_o}}{\mu_o} sin^2 (kx -wt) (\hat j \times \hat k)[/tex]
[tex]S^{\to} (x,t) = \dfrac{{E_o} {B_o}}{\mu_o} sin^2 (kx -wt) \hat i[/tex]
∴
[tex]\mathbf{S^{\to} (x,t) = \dfrac{{E_o} {B_o}}{\mu_o} sin^2 (kx -wt) \hat i }[/tex]
Based on the situation above, choose the CORRECT type of error.
The reading from the timer was not accurate because some of
the timer's display was missing and broken."
Answer:
what's your question I can't understand
Mr Johnson launches an arrow horizontally at a rate of 40m/s off of a 78.4 m cliff towards the south, how much time does it take before the arrow hits the ground below (step 1 of a quesiton will need this answer for a future question)
a 2 seconds
b. 1 second
c.4 seconds
d 19.6
Answer:c
Explanation:
Why do stretching exercises increase flexibility more than cardio exercises?
1. When an object is at rest, not moving, and is crashed into by another
object...which object is experiencing a force and in what direction? Or are
both experiencing a force - what direction?
Answer:
both experience forces or at least a force
Explanation:
it would go in the direction the other object
(second object, the one that crashed) was going
si if going right then right if left then left
plus or minus
An electric motor spins at a constant 2695.0 rpm. If the rotor radius is 7.165 cm, what is the linear acceleration of the edge of the rotor?A) 5707 m/s^2 B) 281.6 m/s^2 C) 28.20 m/s^2 D) 572,400 m/s^2
Answer:
5707 m/s^2
Explanation:
A material that provides resistance to the flow of electric current is called a(n):
circuit
conductor
insulator
resistor
Answer:
it's an insulator
Explanation:
Insulators provides resistance
Answer:
C. insulator
Explanation:
Explane Hawaii characteristics
Answer:
Hawaii is located in the Pacific Ocean to the southwest of the continental U.S., southeast of Japan and northeast of Australia. Hawaii is known for its tropical climate, unique topography, and natural environment, as well as its multicultural population.
what do we call the games that involve different manipulation skills like throwing,tossing,rolling,catching,running,jumping,hopping and stretching what is the answer A.puzzle game B.simulation games C.target games D.role-playing games
A car is traveling west for 12 s its speed is 36.12 m/s in the same direction find the total distance the car traveled
We are given:
constant speed of the car (u) = 36.12 m/s
time in question (t) = 12 seconds
Solving for the Distance and Displacement:
from the second equation of motion:
s = ut + 1/2 at^2
since we have 0 acceleration:
s = ut
replacing the variables
s = 36.12 * 12
s = 433.44 m
Since the car is travelling in a straight line towards the same direction, it's Distance will be equal to its Displacement
Hence, both the Displacement and Distance covered by the car is
433.44 m
but since Displacement also has a direction vector along with it,
the Displacement will be 433.44 m due west
Suppose the flow rate of blood in a coronary artery has been reduced to half its normal value by plaque deposits. By what factor has the radius of the artery been reduced, assuming no turbulence occurs?
Strategy
Assuming laminar flow, Poiseuilleâs law states that
Q = (p2 - p1)pir^4/8nl.We need to compare the artery radius before and after the flow rate reduction.
Answer:
1.18
Explanation:
The flow rate of blood is proportional to the fourth power of its radius as given the Poiseuille's law.
The law is :
[tex]$Q \propto r^4$[/tex]
It is given here that the flood flow rate is been reduced to half its normal value. Therefore, [tex]$Q_1 = \frac{1}{2}Q_2$[/tex]
So, for the radius [tex]$r_1$[/tex] and [tex]$r_2$[/tex], the ratios of their flow rates are :
[tex]$\frac{Q_1}{Q_2}=\frac{r_1^4}{r_2^4}$[/tex]
It is given that the flow rate is reduced to half. So we have,
[tex]$\frac{Q_1}{2Q_1}=\frac{r_1^4}{r_2^4}$[/tex]
or [tex]$r_2=2^{1/4}{r_1}$[/tex]
[tex]$r_2=1.18 \ r_1}$[/tex]
So the radius changes by a factor of 1.18
A car accelerates steadily from 15 m/s to 25 m/s in 5 s. what us its speed
Rita places a 2.5 kg block on a frictionless inclined plane that is 30 degrees above horizontal. She applies a horizontal force, which keeps the block from moving up or down the inclined plane. What is the magnitude of the force Rita applies?
Answer:
14.2
Explanation:
find horizontal force of the weight = 2.5kg x 9.8 Sin30 = 12.3 N
to prevent the sliding she needs to pull horizontally
Fh = 12.3 /Cos 30 =14.2N
Describe and give an example of mutualism.
Describe and give an example of commensalism.
Describe and give an example of parasitism.
Describe and give an example of competition.
Describe and give an example of predation.
Answer:
Mutualism - Bee to flower. Bee eats - flower reproduces
Commensalism - Tree Frog to plant or tree. Frog uses plant for protection.
Parasitism - Flea or tick to host. Parasite feeds off host.
Explanation:
Competition - relationship between organisms that strive for same resources. intraspecific and interspecific. ex) two males competing for mates.
predation - one organism kills and consumes another. wolf hunting moose, cat hunting mouse. venus fly trap killing insect
Skier pushes him self along the snow on flat ground he feels Erizo cents on his body which way
Answer:
Forward
Explanation:
Since the skier pushes himself along the snow on flat ground and he feels air resistance, he will only feels air resistance when he starts moving (unless wind is blowing in opposite direction). The net force vector is dependent on the amount of force applied by the skier here we assume that skier continues to move in forward direction. The net force vector will act in the direction of acceleration, since the skier continues to move in the forward direction, therefore the net force vector will also point in the forward direction.
A 45 kg object has a momentum of 225 kg-m/s northward. What is the object's velocity?
A. 180 m/s
B. 5.0 m/s
C. 10,125 m/s
D. 0.20 m/s
A 40-cm-diameter, 300 g beach ball is dropped with a 4.0 mg ant riding on the top. The ball experiences air resistance, but the ant does not. What is the magnitude of the normal force exerted on the ant when the ball's speed is 4.0 m/s?
Answer:
The normal force exerted on the ant is 0.75 N.
Explanation:
Given;
diameter of the ball, D = 40 cm = 0.4m
radius of the ball, r = 0.2m
mass of the beach ball, m₁ = 300 g = 0.3 kg
mass of the ant, m₂ = 4 x 10⁻⁶ kg
speed of the ball, v = 4 m/s
The area of the ball, assuming spherical ball is given by;
A = 4πr²
A = 4π(0.2)² = 0.5027 m²
The drag force (resistance) experienced by the spherical ball is given as;
[tex]F_D = \frac{1}{2}C\rho Av^2[/tex]
where;
C is the drag coefficient of the spherical ball = 0.45
ρ is density of air = 1.21 kg/m³
[tex]F_D = \frac{1}{2}C\rho Av^2\\\\F_D = \frac{1}{2}(0.45)(1.21) (0.5027)(4)^2\\\\F_D = 2.19 \ N[/tex]
The downward force of the ball due to its weight and that of the ant is given by;
[tex]F_g = mg\\\\F_g =g(m_{ant} + m_{ball})\\\\F_g = g(4*10^{-6} \ kg\ + \ 0.3\ kg)\\\\F_g = g(0.300004 \ kg) \ \ \ (mass \ of \ the \ ant \ is \ insignificant)\\\\F_g = 9.8(0.3)\\\\F_g = 2.94 \ N[/tex]
The net downward force experienced by the ball is given by;
[tex]F_{net} = F_g - F_D\\\\F_{net} = 2.94 \ N - 2.19 \ N\\\\F_{net} = 0.75 \ N[/tex]
This downward force experienced by the ball is equal to the normal reaction it exerts on the ant.
Thus, the normal force exerted on the ant is 0.75 N.
An electron is accelerated from rest through a potential difference of 300V. it then passes through a uniform 0.001-T magnetic field, oriented perpendicular to the electrons velocity. what is the magnitude of the magnetic force on the electron?
Given :
Potential difference, V = 300 V.
Magnetic Field, B = 0.001 T.
To Find :
The magnitude of the magnetic force on the electron.
Solution :
We know, for perpendicular orientation, force is given by :
[tex]F = qVB\\\\F = 1.6 \times 10^{-19} \times 300\times 0.001\ N\\\\F = 4.8\times 10^{-20}\ N[/tex]
Hence, this is the required solution.
A 36.3 kg cart has a velocity of 3 m/s. How much kinetic energy does the object have?
Answer:
163.35
__________________________________________________________
We are given:
Mass of the object (m) = 36.3 kg
Velocity of the object (v) = 3 m/s
Kinetic Energy of the object:
We know that:
Kinetic Energy = 1/2(mv²)
KE = 1/2(36.3)(3)² [replacing the variables with the given values]
KE = 18.15 * 9
KE = 163.35 Joules
Hence, the cart has a Kinetic Energy of 163.35 Joules