Answer:
Explanation:
radius of circle r = 0.9 m.
(a ) In a motion on circular path , work done is zero because force ( centripetal force ) acts perpendicular to displacement .
( b )
Tension in string T = m ω²r
Putting the values
60 = .072 x ω² x 0.9
ω² = 926
ω = 30.4 rad /s
angle made in 20 revolutions θ = 20 x 2π = 126.6 rad
time taken = θ / ω
= 126.6 / 30.4
= 4.16 s .
PLEASE ANSWER THIS WILL MARK AS BRAINLIEST PLEASE PUT TRUE ANSWERS
Charles Darwin developed the theroy of Natural Selection (Survival of the Fittest). Which statment below describes this concept?
A.
Animals with the best DNA will go extinct
B.
Organisms will adapt only to be able to have a food source
C.
Organisms that are only single cells will survive any environment
D.
Animals with the best genes and that have the ability to adapt will survive
Answer:
D
Explanation:
A is wrong bc best DNA will survive
B is wrong because organism adapt not only for food source but to be able to live in the environment as well
C is wrong because single celled organisms don't adapt
You have a hand-crank generator with a 100-turn coil (each turn having an area of 0.0350 m2), which can spin through a uniform magnetic field that has a magnitude of 0.0500 T. You can turn the crank at a maximum rate of 3 turns per second, but the hand crank is connected to the coil through a set of gears that makes the coil spin at a rate 6 times larger than the rate at which you turn the crank. What is the maximum emf you can expect to get out of this generator
Answer:
Explanation:
Maximum emf produced = nωAB. where n is no of turns , A is area , B is magnetic field and ω is angular velocity .
n = 100 , A = .035 m²
B = .05 T
ω = 2π f , f is no of revolution per second by coil
= 2 x 3.14 x 6 x 3
= 113.04 rad /s
Maximum emf produced = 100 x 113.04 x .035 x .05
= 19.78 volt .
HURRYYYYY, FASTTT, HELPPP What is the consequence of atoms being a singular closed system?
Atoms of a certain element contain a fixed amount of energy.
Atoms of a certain element can’t be altered by outside forces.
Atoms don’t interact with each other in any way.
Atoms decompose slowly over time as they lose energy.
1
Answer:
Atoms of a certain element contain a fixed amount of energy.
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such defines the structure of a chemical element.
Generally, these atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
Additionally, all the physical properties of a mineral result from the mineral's internal arrangement of atoms.
The consequence of atoms being a singular closed system is that atoms of a certain element contain a fixed amount of energy because the number of protons, neutrons and electrons are in a fixed proportion.
What is the formula for Ba+2 and F-?
Answer:
BaF2
Explanation:
since you got the valence numbers just do the scissors move where you:
give the F the 2 and give the Ba the 1 so it be like
BaF2 here is the chemical compound
A hot air balloon is rising at a speed of 10 km/hr. One hour later, the balloon
is still rising at 10 km/hr. What is its acceleration?
Which graph represents the relationship between the magnitude of the gravitational force exerted by earth on a spacecraft the distance between the center of the spacecraft the center of earth
Answer:
B as distance increase force decrease, but it is not a linear relationship.
what is angle of deviance in physics
The angle of deviation is defined as the angle which is obtained from the difference between the angle of incidence and the angle of refraction created by the ray of light travelling from one medium to another that has a different refractive index. I hope this helps you
10 POINTSSS
My teacher said these are wrong and I'm confused. The blanks need filled.
All objects will remain at rest, or will continue to move at a constant speed in the same ______ unless acted upon by an unbalanced force. This property is called inertia.
Unbalanced forces cause an object to _______.
DONT PUT: VELOCITY, AND CHANGE IN MOTION.
Answer:
Direction & accelerate
Answer:
unbalanced forces cause an object to accelerate
One of alcohol's effects is to _____.
Answer:
slow down your reaction time
Explanation:
because alcohol makes nerve cells in the brain less excited and basically slows them down.
Activities:
1. Name the instrument that is used to measure Air Pressure.
2.Explain what is Cyclone and Anticyclone
Answer: barometer.
A cyclone is a storm or system of winds that rotates around a center of low atmospheric pressure. An anticyclone is a system of winds that rotates around a center of high atmospheric pressure.
A comet is in an elliptical orbit around the Sun. Its closest approach to the Sun is a distance of 4.8 1010 m (inside the orbit of Mercury), at which point its speed is 9.1 104 m/s. Its farthest distance from the Sun is far beyond the orbit of Pluto. What is its speed when it is 6 1012 m from the Sun
Answer:
Explanation:
From the given information:
Distance [tex]d_i = 4.8 \times 10^{10} \ m[/tex]
Speed of the comet [tex]V_i = 9.1 \times 10^{4} \ m/s[/tex]
At distance [tex]d_2 = 6 \times 10^{12} \ m[/tex]
where;
mass of the sun = [tex]1.98 \times 10^{30}[/tex]
[tex]G = 6.67 \times 10^{-11}[/tex]
To find the speed [tex]V_f[/tex]:
Using the formula:
[tex]E_f = E_i + W \\ \\ where; \ \ W = 0 \ \ \text{since work done by surrounding is zero (0)}[/tex]
[tex]E_f = E_i + 0 \\ \\ K_f + U_f = K_i + U_i \\ \\ = \dfrac{1}{2}mV_f^2 + \dfrac{-GMm}{d^2} = \dfrac{1}{2}mV_i^2+ \dfrac{-GMm}{d_i} \\ \\ V_f = \sqrt{V_i^2 + 2 GM \Big [ \dfrac{1}{d_2}- \dfrac{1}{d_i}\Big ]}[/tex]
[tex]V_f = \sqrt{(9.1 \times 10^{4})^2 + 2 (6.67\times 10^{-11}) *(1.98 * 10^{30} ) \Big [ \dfrac{1}{6*10^{12}}- \dfrac{1}{4.8*10^{10}}\Big ]}[/tex]
[tex]\mathbf{V_f =53.125 \times 10^4 \ m/s}[/tex]
g Consider a beach ball bobbing up and down in the center of a swimming pool. Imagine that the ball remains at the same position at the center of the pool. The illustration below shows several consecutive wave crests at one instant of time. Suppose that observer A is moving toward the source and observer B is moving away from the source. Discuss with your group: does A or B observe higher frequency water wave vibrations, or do they observe the same frequency vibrations
Answer:
For the observer approaching the source, the frequency increases
for the observer who moves away from the source the frequency decreases
Explanation:
This is an example of relative movement between the waves and the observer, let's first examine the observer A, they tell us that it is approaching the wave source (ball).
For waves there is a relationship between their speed, wavelength and frequency
v = λ f
the observed frequency if the relative velocity is zero
f₀ = v /λ₀
in this case the observer is approaching the source therefore the velocity is
v ’= v₀ + u
where u is the velocity of the observer
as the emission source remains fixed the wavelength does not change
v’= λ₀ f’
f ’= v’ /λ₀
f ’= [tex]\frac{v+u}{\lambda_o }[/tex]
we substitute the value of the wavelength
λ₀ = v / fo
f’= [tex]\frac{v+u}{v} \ f_o[/tex]
we can see that the frequency increases
for the case of observer B moving away from the source the relative velocity is
v ’= v-u
by substituting in the equation
f ’= v’ /λ₀
f ’= [tex]\frac{v-u}{\lambda_o}[/tex]v-u / lam
f ’= [tex]\frac{v-u}{v} \ f_o[/tex]
in this case the frequency decreases
In conclusion:
For the observer approaching the source, the frequency increases
for the observer who moves away from the source the frequency decreases
The observer A who is moving towards the source observe higher frequency water wave vibrations than the observer B.
What is frequency?Frequency of wave is the number of waves, which is passed thorough a particular point at a unit time. It can be given as,
[tex]f=\dfrac{v}{\lambda}[/tex]
Here, (λ) is the wavelength of the wave and (v) is the speed of the wave.
The beach ball bobbing up and down in the center of a swimming pool. The ball remains at the same position at the center of the pool.
The observer A is moving toward the source. The frequency received by A will be,
[tex]f'=f_o\left(\dfrac{v+u}{v}\right)[/tex]
Here, [tex]f_o[/tex] is the natural sound source, u is the velocity of the observer and v is the velocity of sound propagation.
The observer B is moving away from the source. The frequency received by A will be,
[tex]f"=f_o\left(\dfrac{v-u}{v}\right)[/tex]
In this case the frequency of the observer who is approaching to the source will be increases and the frequency of the observer who is leaving the source will be decreases.
Thus, the observer A who is moving towards the source observe higher frequency water wave vibrations than the observer B.
Learn more about the frequency here;
https://brainly.com/question/1436295
Two wheels with identical moments of inertia are rotating about the same axle. The first is rotating clockwise at 2.0 rad/s, and the second is rotating counterclockwise at 6.0 rad/s. If the two wheels are brought into contact so that they rotate together, their final angular velocity will be
Answer:
w = 2 rad / s counterclockwise
Explanation:
This is an exercise in angular momentum, we define a system formed by the two wheels in such a way that the torques during contact have been internal and the angular moeoto0o is conserved
L₀ = L_f
We assume that the counterclockwise rotations are positive, let's look for the initial moment before the collision
L₀ = I w₁ + I w₂
where the angular velocity of the first wheel is w₁ = - 2.00 rad / s and the angular velocity of the second wheel is w₂ = 6.0 rad / s
As the wheels collide and remain in unity, the final angular momentum after the collision
I_total = 2 I
L_f = I_total w
we substitute
I w₁ + I w₂ = I_total w
w = [tex]\frac{I w_1 + Iw_2}{I_{total} }[/tex]
w = [tex]\frac{I \ (w_1+w_2)}{2 \ I}[/tex]
w = [tex]\frac{w_1 +w_2}{2}[/tex]
let's calculate
w = [tex]\frac{-2.0 + 6.0}{2}[/tex]
w = 2 rad / s
the positive sign indicates that the rotation is counterclockwise
The final angular velocity will be 2 rad /s counterclockwise. The pace of transition of angular displacement is described as angular velocity.
What is angular velocity?The rate of change of angular displacement is defined as angular velocity and it is stated as follows:
ω = θ t
The given data in the problem is;
[tex]\omega_1[/tex] is the angular velocity of wheel 1= 2.0 rad/s
[tex]\omega_2[/tex] is the angular velocity of wheel 2= 6.0 rad/s
[tex]\rm \omega_f[/tex] is the final angular velocity=?
As the wheel collides the initial momentum is equal to the final momentum;
Momentum before collision
[tex]\rm L_0 = I \omega_1 + I \omega_2[/tex]
Momentum after the collision when the two-wheel becomes one wheel;
[tex]\rm \I_ {total }= 2 I \\\\ L_f= I_{total}\omega \\\\[/tex]
From the conservation of momentum principle;
[tex]\rm L_i = L_f \\\\ I \omega_1 + I \omega_2 = I_{total}\omega \\\\ \rm \omega= \frac{ I \omega_1 + I \omega_2 }{2I} \\\\ \omega = \frac{\omega_1 + \omega_2}{2} \\\\[/tex]
[tex]\omega=\frac{-2.0+ 6.0}{2} \\\\ \omega=2\ rad/sec[/tex]
Hence the final angular velocity will be 2 rad /s counterclockwise.
To learn more about the angular velocity refer to the link;
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Suppose you are watching an ice-hockey game with some classmates. As the puck is sliding across the ice at a relatively constant speed, it passes close to a player, who hits it (with his stick) in the same direction as it is already moving. After the hit, you notice that the puck is moving much faster than it was before the hit. Your classmates propose the following three explanations for why the puck is moving faster after the hit than before. Whose reasoning do you agree with?
Student A: "The force of the stick was transferred to the puck during the hit. After the hit, the puck has more force, so it moves faster."
Student B: "The puck still has the force that started it moving, which is what keeps it moving at a constant speed. When the player hit it, he adds to this force, which makes the speed of the puck increase. After the hit, this extra force is gone, so the puck stops increasing its speed, but the original force is still there so now it moves at a faster constant speed."
Student C: "While the stick is in contact, it applies a force to the puck that makes its speed increase. As soon is contact is lost, this force disappears, so the speed of the puck stops increasing."
Answer:
the answer, the correct one is C
Explanation:
Let's propose the solution of this problem to know which explanation is correct, when the concha stick with the disc is an impulse exercise
I = ΔP
∫ F dt = pf-po
∫ F dt = m v_f - m v₀
Therefore, during the time that the contact lasts, a force is applied to the disk, which causes that if the amount of movement increases and therefore its speed increases, when the constant ceases the forces are reduced to zero and the disk no longer changes its momentum following with constant velocity.
When reviewing the answer, the correct one is C
A blender has a power of 0.3 kW. It is used to make a fruit smoothie, which takes 50 seconds. How much energy is used? Give your answer in kilojoules.
Answer:
P=W/t
W=Pt=0.3kWx50s=15KJ
We have that the energy is used by a blender that has a power of 0.3 kW and which takes 50 seconds is
W=15KJ
From the question we are told
A blender has a power of 0.3 kW. It is used to make a fruit smoothie, which takes 50 seconds. How much energy is used? Give your answer in kilojoulesGenerally the equation for the Power is mathematically given as
P=W/t
Therefore
W=Pt
W=0.3*50
W=15KJ
Therefore
The energy is used by a blender that has a power of 0.3 kW and which takes 50 seconds is
W=15KJ
For more information on this visit
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2.Test the age of your eyes. a.Hold a pencil or ballpoint pen vertically at arm's length. b.Close your left eye and focus on the tip. c.Quickly bring the pencil closer to your eye until it is out of focus. d.Have your partner measure the distance between your eye and the pencil. e.Repeat for both eyes. f.Try it with and without glasses (if you wear glasses). Age of your Eyes Cm91013185083
Answer:
See Explanation
Explanation:
Given
Steps: a - f
Table
[tex]\begin{array}{ccccccc}{cm} & {9} & {10} & {13} & {18} & {50} & {83} \ \\ {Age} & {10} & {20} & {30} & {40} & {50} & {60} \ \end{array}[/tex]
Note that: The question is a practical question and the result may differ base on individuals and environment.
So, I will pick up the question from how to determine the age of the eye after the distance between the eyes and the pencil has been established
In my case, the measurement is:
[tex]Length= 10.4[/tex]
Approximate
[tex]Length= 10[/tex]
From the above table, the corresponding age to 10cm is:
[tex]Age = 20cm[/tex]
If in your measurement, the length is approximately (for example):
[tex]Length = 9cm[/tex]
The age will be:
[tex]Age = 10[/tex]
A scientist analyzes the light from a distant galaxy and finds that it is shifted to the longer wavelength of the electromagnetic spectrum. What does this data help to study?
1) the color of the galaxy
2) the distance of the galaxy from Earth
3) the existence of life on any planet in the galaxy
4) the study of the amount of light scattered by dust in space
Answer:
Option 2
Explanation:
As per the relation between the distance of the galaxy and shifting of the light of the galaxy towards any specific wavelength of the electromagnetic spectrum, a galaxy at great distance shifts more towards the red spectra that has the highest wavelength.
Thus, this observation give details about the distance of the galaxy from earth.
Answer:
b
Explanation:
What affects the amount of rock that water can erode?
Speed
Time
Slope
All of the above
objects 1 and 2 attract each other with a electrostatic force of 36.0 units
Answer:
F' = 9F
Explanation:
The complete question is "Objects 1 and 2 attract each other with a electrostatic force of 36.0 units. If the charge of Object 2 is tripled, then the new electrostatic force will be _____ units".
The electric force is given by :
[tex]F=\dfrac{kq_1q_2}{r^2}[/tex]
If F = 36 units,
[tex]36=\dfrac{kq_1q_2}{r^2}\ ...(1)[/tex]
If charges are tripled, q₁' = q₂' = 3q₁ and 3q₂
So,
[tex]F'=\dfrac{kq_1'q_2'}{r^2}\\\\F'=\dfrac{k\times 3q_1'\times 3q_2'}{r^2}\\\\F'=9\times \dfrac{kq_1'q_2'}{r^2}\\\\F'=9F[/tex]
So, the new force becomes 9 times of the initial force.
Which of the following equations illustrates the law of conservation of
matter?
Answer:
A
Explanation:
the balancing is correct in the first one
· A wave with a frequency of 10 Hz and wavelength of 12m has what speed?
What is your hypothesis (or hypotheses) for this experiment?
(about Thermal Energy Transfer)
Answer:
I hypothesis that the motion involving the balls in the experiment were moving to create data.
Explanation:
I hope this helps!
Which level of organization is all the same type of ecosystem found on Earth
that share common characteristics?
A biome, in simple terms, is a set of ecosystems sharing similar characteristics with their abiotic factors adapted to their environments.
What minimum speed must the block have at the base of the 70 m hill to pass over the pit at the far (right-hand) side of that hill and reach the other side (at a 50 m level)
Answer:
initial velocity is v = 4.95 m / s
Explanation:
To solve this exercise we use the projectile launch ratios, when the block leaves the hill its speed is horizontal, let's find the time it takes to fall to the other point.
Initial vertical velocity is zero
y = y₀ + v_{oy} t - ½ g t²
y-y₀ = 0 -1/2 g t²
t = [tex]\sqrt{ \frac{ 2(y_o -y)}{g} }[/tex]
calculate
t = [tex]\sqrt{ \frac{2 ( 70-50)}{9.8} }[/tex]
t = 2.02 s
with this time we can substitute in the horizontal displacement equation
x = v₀ₓ t
v₀ₓ = x / t
suppose that the distance between the two points is x = 10 m
v₀ₓ = 10 / 2.02
v₀ₓ = 4.95 m / s
initial velocity is v = 4.95 m / s
Match the following:
machinery part :nickel or chromium
ornamentation and decoration pieces :silver and gold
processed food :tin coated iron can
bridges and automobiles :zinc metal
distilled water:bad conductor
Answer:
iron metal :chromium
machinery part :nickel or chromium
ornamentation and decoration pieces :silver and gold
processed food :tin coated iron can
bridges and automobiles :zinc metal
distilled water:bad conductor
Explanation:
In 1656, the Burgmeister (mayor) of the town of Magdeburg, Germany, Otto Von Guericke, carried out a dramatic demonstration of the effect resulting from evacuating air from a container. It is the basis for this problem. Two steel hemispheres of radius 0.380 m (1.25 feet) with a rubber seal in between are placed together and air pumped out so that the pressure inside is 17.00 millibar. The atmospheric pressure outside is 950 millibar. Calculate the force required to pull the two hemispheres apart.
Answer:
F = 42325.17 N
Explanation:
We are given;
Radius of hemispheres; r = 0.38 m
Inner pressure; P_i = 17 milli bar
Outside Pressure; P_o = 950 milli bar
Now, net pressure; P_net = P_o - P_i
P_net = 950 - 17
P_net = 933 milli bar
From conversion rates, we know that;
1 milli bar = 100 N/m²
Thus;
P_net = 933 × 100
P_net = 93300 N/m²
Surface Area of hemisphere; A = πr²
A = π × 0.38²
Now, formula for pressure is;
P = F/A
Where F is force.
Thus making F the subject;
F = P × A
Plug in P_net and A to get;
F = 93300 × π × 0.38²
F = 42325.17 N
Build a second circuit with a battery and a light bulb but this time add a switch. Your circuit might look something like the one at right. When a switch is open in a circuit, it means the two ends are disconnected and current cannot flow between them. When a switch is closed in a circuit, it means the two ends are connected and current can flow between them. Play with the switch to check how it affects the flow of current. With the switch closed, compare the brightness of the bulb and the flow of current in this circuit, with that of your first circuit. Did increasing the length of wire in the circuit change the brightness of the bulb or the curr
Answer:
the resistance of the wire has no effect on the brightness of the bulb.
Explanation:
Let's apply ohm's law for your light bulb circuit plus wires plus switch
V = I R_{bulb} + I R_ {wire}
the current in a series circuit is constant
V = I (R_{bulb} + R_{wire})
To know the effect of the wires on the brightness of the bulb, we must look for the value of the typical resistance of these elements.
Incandescent bulb
Power 60 W
let's use the power ratio
P = V I = V2 / R
R = V2 / P
the voltage value for this power is V = 120 V
R = 120 2/60
R_bulb = 240 Ω
Resistance of a 14 gauge copper wire (most used), we look for it on the internet
R = 8.45 Ω/ km
in a laboratory circuit approximately 2 m is used, so the resistance of our cable is
R = 8.45 10⁻³ 2
R_wire = 0.0169 Ω
let's buy the two resistors
R_{bulb} = 240
R_{wire} = 0.0169
[tex]\frac{R_{bulb} }{R_{wire} } = \frac{240 }{ 0.0169}[/tex]
[tex]\frac{ R_{bulb} }{ R_{wire} } = 1.4 \ 10^4[/tex]
therefore resistance of the bulb is much greater than that of the wire, therefore almost all the power is dissipated in the bulb.
In summary, the resistance of the wire has no effect on the brightness of the bulb.
A hard rubber ball on a string is being used as a pendulum. When you first look at the pendulum, the ball is being held to one side with the string fully extended. Suddenly, the ball is released from rest and allowed to swing back and forth. For the first three or four swings, the ball almost reaches the height from which it was released. However, after a long time has passed, the ball finally comes to rest, hanging straight down. (a) If the ball has a mass of 6.5 kg and is released from a height of 76 cm above its final resting height, find the amount of additional thermal energy that now exists in the air, the ball, the string, and the pivot of the pendulum. Give your answer in joules. (No Response) J (b) Answer the same question in kilocalories rather than joules.
Answer:
a) Q = 48.42 J, b) Q = 1,157 10⁻² Kcal
Explanation:
a) In this exercise we fear an initial energy
starting point. Higher
Em₀ = U = m g h
let's calculate
Em₀ = 6.5 9.8 0.76
Em₀ = 48.42 J
This energy is transformed by non-conservative forces into heat, they indicate that in air, as energy is not lost and there is no work since the displacement is zero
Em₀ = Q
Q = 48.42 J
b) reduce to kc
Q = 48.42 J (kc / 4184 J)
Q = 1,157 10⁻² Kcal
A kite 40 ft above the ground moves horizontally at a constant speed of 10 ft/s, with a child, holding the ball of kite string, standing motionless on the ground. Assume the kite is flying away from the child. At what rate is the child releasing the string when (a) 50 ft of the string is out
Answer:
v = 27.28 m /s, θ = 63.9º
Explanation:
For this exercise we can approximate the movement to a projectile launch, let's analyze the situation.
* We must find the horizontal speed, for this we will find the descent time and the horizontal distance
* We look for the vertical speed
At the highest point the speed is horizontal
Let's find the time it takes for the kite to reach the ground
y = y₀ + v_{oy} t - ½ g t²
0 =y₀ + 0 -1/2 gt²
t = [tex]\sqrt{ \frac{2y_o}{g} }[/tex]
t = √(2 40/32)
t = 2.5 s
to find the horizontal velocity we must know the horizontal distance, let's use trigonometry
sin θ = y / l
θ = sin⁻¹1 y / l
θ = sin⁻¹ 40/50
θ = 53.1º
therefore the horizontal distance is
x = l cos 53.1
x = 50cos 53.1
x = 30 m
let's use the equation
x = v₀ₓ t
v₀ₓ = x / t
v₀ₓ = 30 / 2.5
v₀ₓ = 12 m / s
we look for the vertical component of the velocity
v_y = v_{oy} - g t
v_y = 0 - g t
v_y = - 9.8 2.5
v_y = -24.5 m / s
the negative sign indicates that the speed is directed downwards, because it is the arrival point, as they indicate that there is no friction, the exit speed is the same, worse with the opposite sign
We already have the two components of the velocity, let's use the Pythagorean theorem to find the modulus
v = [tex]\sqrt{v_x^2 + v_y^2}[/tex]
v = [tex]\sqrt{12^2 + 24.5^2}[/tex]
v = 27.28 m /s
we use trigonometry for the angle
tan θ = v_y / vₓ
θ = tan⁻¹ v_y / vₓ
θ = tan⁻¹ 24.5 / 12
θ = 63.9º
Which of the following solar phenomena is likely to have the most negative impact on Earth?
A solar flare as it may cause brief radio blackouts
An aurora as it may damage communication networks
An aurora as it may cause worldwide transmission problems
A solar flare as it may harm satellites and aircrafts flying near poles
Answer:
A solar flare as it may harm satellites and aircrafts flying near poles
Explanation:
Since solar flare is electro magnetic waves going to Earth the waves will mostly get absorbed by the north and south poles resulting in the aurora borealis, but if the solar flare is strong enough it may stop communications and engines in satellites and aircrafts and in result harming them
Answer:
A solar flare as it may harm satellites and aircrafts flying near poles
Explanation: