Answer:
a) t = 20 s, b) x = 1000 m, As the runway is only 800 m long, the plane cannot land at this distance
Explanation:
This is a kinematics exercise
a) in minimum time to stop,
v = vo + at
v = 0
t = -v0 / a
we calculate
t = -100 / (5.00)
t = 20 s
b) Let's find the length you need to stop
v² = vo² + 2 a x
x = -v0 ^ 2 / 2a
x = - 100² / 2 (-5.00)
x = 1000 m
As the runway is only 800 m long, the plane cannot land at this distance.
the unit of energy is same as that of work i.e joule give reason
"Energy" is the ability to do work.
"Work" is the process of using energy.
What kind of waves are present during an earthquake?
Answer:
There are four main types of earthquake waves:
P-waves S-waves (which are body waves), Rayleigh waves Love waves (which are surface waves).HOPE IT HELPS!!
Why does time have a direction? Please give your ideas I want to see them. Brainliest f0r most effort.:)
Answer:
it's a rule like water !!!!
Explanation:
Most importantly, time appears to run forward always never backwards. in other words there's perceived arrow of time and there's thermodynamic arrow of time, and they always point in a forward direction
for every system there are more states that seem chaotic then states that seem ordered.
the arrow of time seems to have something to do with that tendency. but to get from one instance to another where things get more entropy, we already need some kind of time, gotta admit that.
some (physicists) believe that time is an illusion, that the whole universe is already set in stone, like a block (the idea is therefore called block universe). from the perspective of a godlike outside observer the universe would be like a book, or a 4D movie. the characters might feel a movement of things in a direction, but rewinding it wouldn't feel different in any instance because the order in wich things happen is already written.
a different idea is that there are infinite many different futures and the further they are away, the less we can know for sure about them in a physical way. and this might also be work for the past, so that different parts could lead to one present.
when macroscopic information is deleted, it might not be reversible, so the past gets ultimately blurry. one example for deletion of macroscopic information this is the Library of Alexandria wich burned down.
all the quantum information is still conserved, but the order of things (like letters on pages) is lost and could have been in different configurations before. we can't ultimately not even see the past, as much as we would try.
personally the idea that the past is written in stone but the future is in flux doesn't make any sense for me. because than I could have free will now, but not from the perspective 10 days later.
the present would be a very special thing than, the stage where the universe likes to play.
maybe we can get a grasp on time if we look at it like rules for a game, like a cardboard game.
To get from one configuration to the next ,we must follow rules. like throwing dice and moving in monopoly.
gravity would be a simple real world example for such a rule, a natural law.
But no one would have a firm clue where this rules came from.
TLDR: I don't know and neither does anyone else for sure, not even top notch scientists.
the hardest questions are easy to formulate, but maybe even impossible for us to answer in a satisfying way. I hope we will understand those hard questions better one day, and maybe even get answers.
What is the direction of the magnetic field due to the positive charge at the location of the negative charge
Answer:
A positively charged object moving due west in a region where the Earth's magnetic field is due north experiences a force that is straight down as shown.
A negative charge moving in the same direction would feel a force straight up.
at which point is the Kinetic energy the lowest?
Answer:
the lowest kinetic energy point is option D
The reservoir stores 6 500 000 m3 of water. The density of the water is 998 kg/m3. Calculate the mass of water in the reservoir. Give your answer in standard form.
Answer:
Mass = 64,870,000,000 kilograms
Explanation:
Given the following data;
Density = 998 kg/m³
Volume = 6,500,000 m³
To find the mass of water in the reservoir;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
Density = mass/volume
Making mass the subject of formula, we have;
Mass = density * volume
Mass = 998 * 6,500,000
Mass = 64,870,000,000 kilograms
A boy im50kg at rest on a skateboard is pushed by another boy who exerts a force of 200 N on him. If the first boy's
final velocity is 8 m/s, what was the contact time?
seconds
Answer:
Time, t = 2 seconds
Explanation:
Given the following data;
Mass, m = 50 kg
Initial velocity, u = 0 m/s (since it's starting from rest).
Final velocity, v = 8 m/s
Force, F = 200 N
To find the time, we would use the following formula;
[tex] F = \frac {m(v - u)}{t} [/tex]
Making time, t the subject of formula, we have;
[tex] t = \frac {m(v - u)}{F} [/tex]
Substituting into the formula, we have;
[tex] t = \frac {50(8 - 0)}{200} [/tex]
[tex] t = \frac {50*(8)}{200} [/tex]
[tex] t = \frac {400}{200} [/tex]
Time, t = 2 seconds
It takes 130 j of work to compress a certain spring 0.10m. (a) what is the force constant of this spring? To compress the spring an additional 0.10m, does it take 130
Answer:
Explanation:
The PE equation for a mass/spring system is
[tex]PE=\frac{1}{2}k[/tex]Δx² and filling in:
[tex]130=\frac{1}{2}k(.10)^2[/tex] and
[tex]k=\frac{2(130)}{(.10)^2}[/tex] so
k = 26000 N/m
If the displacement from equilibrium changes more, the PE needed to compress it will also change.
[tex]PE=\frac{1}{2}(26000)(.20)^2[/tex] gives us that
PE = 520J
The picture below shows a person swinging a yo-yo in a circle. Which vector shows the velocity of the yo-yo at this moment?
A. B
B. A
C. C
D. D
An object weighs 2.2 pounds on Earth and has a mass of 1 kilogram. What are the weight and mass of the same object in space where there is no gravity acting on it?
Answer:
Heavier than 2.2 pounds
Explanation:
A spherical cell has a radius of 2.3 μm , and the phospholipid bilayer that constitutes its membrane has a thickness of 3.75 nm . At its normal resting state, the outer membrane is at a voltage of 0V, and the inner membrane is at a voltage of -70mV. The dielectric constant of the cell membrane is roughly 9.0. What is the capacitance of the cell? (Note: the surface area of a sphere is 4πr2)
Answer:
Explanation:
The cell is acting like a shell .
Capacity of a shell is given by the following expression.
C= 4πk ε₀ x ab / (b-a )
k is dielectric constant , b and a are outer and inner radius ε₀ is a constant .
Here a = 2.3 x 10⁻⁶ m
b = 2.3 x 10⁻⁶ + .00375 x 10⁻⁶
= 2.30375 x 10⁻⁶ m
b -a = 3.75 x 10⁻⁹ m .
k = 9
4π ε₀ = 1 / 9 x 10⁹ = .111 x 10⁻⁹
C= .111 x 10⁻⁹ x 9 x 2.3 x 10⁻⁶ x 2.30375 x 10⁻⁶ / 3.75 x 10⁻⁹
= 1.41 x 10⁻¹² F
= 1.41 pF .
A mass that weighs 8 lb stretches a spring 24 in. The system is acted on by an external force of 4 sin 4t lb. If the mass is pulled down 6 in. and then released, determine the position of the mass at any time. Determine the first four times at which the velocity of the mass is zero
Answer:
[tex]t = \frac{\pi}{8}, \frac{\pi}{4}, \frac{3\pi}{8}, \frac{3 \pi}{4}[/tex]
Explanation:
The equation of force is
F = 4 sin 4 t
Compare with the standard equation
f = A sin wt
where, w is the angular frequency and A is the amplitude.
Now
w = 4 rad/s
Let the time period is T.
the relation for the time period is
[tex]T = \frac{2\pi}{w}\\\\T = \frac{2 \pi}{4}\\\\T = \frac{\pi}{2}[/tex]
the time period is defined as the time taken by the body to complete one oscillation.
So, the velocity is zero at the extreme points where the object is at time, T/4 and its odd T/2, 3T/4, 3T/2, etc.
So, the velocity is zero at time
[tex]t = \frac{\pi}{8}, \frac{\pi}{4}, \frac{3\pi}{8}, \frac{3 \pi}{4}[/tex]
An amoeba has 1.00 x 1016 protons and a net charge of 0.300 pC. Assuming there are 1.88 x 106 fewer electrons than protons, If you paired them up, what fraction of the protons would have no electrons
Answer:
The fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]
Explanation:
We are given that
Amoeba has total number of protons=[tex]1.00\times 10^{16}[/tex]
Net charge, Q=0.300pC
Electrons are fewer than protons=[tex]1.88\times 10^6[/tex]
We have to find the fraction of protons would have no electrons.
The fraction of the protons would have no electrons
=[tex]\frac{Fewer\;electrons}{Total\;protons}[/tex]
The fraction of the protons would have no electrons
=[tex]\frac{1.88\times 10^{6}}{1.00\times 10^{16}}[/tex]
[tex]=1.88\times 10^{-10}[/tex]
Hence, the fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]
Does this equation show that transmutation has taken place during decay?
Why or why not?
Ni – S.Ni+y
A. No, because there is conservation of the number of atoms as well
as the number of nucleons.
B. No, because high-energy electromagnetic waves are emitted.
C. Yes, because the numbers of nucleons and atoms are conserved.
D. Yes, because nickel atoms remain nickel atoms with the same
number of neutrons.
Answer:
Maybe A is the correct answer
Suppose that you are standing on a train accelerating at 0.20g (where g is the acceleration due to gravity). What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide
Answer:
0.2
Explanation:
The given parameters are;
The acceleration of the train, a = 0.2·g
The mass of the person standing on the train = m
Let μ represent the coefficient of static friction, we have;
The force acting on the person, F = m × a = m × 0.2·g
The force of friction acting between the feet and the floor, [tex]F_f[/tex] = m·g·μ
For the person not to slide we have;
The force acting on the person = The force of friction acting between the feet and the floor
F = [tex]F_f[/tex]
∴ m × 0.2·g = m·g·μ
From which we get;
0.2 = μ
The coefficient of static friction that must exist between the feet and the floor if the person is not to slide, μ = 0.2.
If you are driving 90 km/hkm/h along a straight road and you look to the side for 2.8 ss , how far do you travel during this inattentive period
Answer:
Distance = 70 meters
Explanation:
Given the following data;
Speed = 90 km/h
Time = 2.8 seconds
Conversion:
90 km/h to meters per seconds = 90 * 1000/3600 = 90000/3600 = 25 m/s
To find the distance covered during this inattentive period;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
[tex]Speed = \frac{distance}{time}[/tex]
Making distance the subject of formula, we have;
[tex] Distance = speed * time [/tex]
Substituting into the above formula, we have;
[tex] Distance = 25 * 2.8 [/tex]
Distance = 70 meters
A piano string of density 0.0050 kg/m is under a tension of 1,350 N. Find the velocity with which a wave travels on the string.
Answer:
519.62 m/s
Explanation:
Applying,
v = √(T/m').............. Equation 1
Where v = velocity of the wave, T = Tension on the string, m' = mass per unit length of the string
From the question,
Given: T = 1350 N, m' = 0.005 kg/m
Substitute these values into equation 1
v = √(1350/0.005)
v = √(270000)
v = 519.62 m/s
What happens to the electric force between two particles if the distance
between them is doubled?
A. It decreases to half the original force.
B. It increases to twice the original force.
C. It increases to 4 times the original force.
D. It decreases to 1/4 of the original force.
Answer:
D.
Explanation:
Force and distance are inversely related, so a greater distance results in a weaker force.
a trampoline launches a 50kg person 2m into the air. if the springs push with 1960N of force, how much displacement was there in the trampoline
Answer: 0.5 m
Explanation:
Given
Mass of the person is [tex]m=50\ kg[/tex]
Trampoline launches the person into the air up to height of [tex]h=2\ m[/tex]
Force experience by springs is [tex]F=1960\ N[/tex]
Here, the work done on displacing the springs is equivalent to the Potential energy acquired by the person i.e.
[tex]\Rightarrow F\cdot x=mgh\quad [\text{x=displacement of the trampoline}]\\\\\text{Insert the values}\\\\\Rightarrow x=\dfrac{50\times 9.8\times 2}{1960}\\\\\Rightarrow x=\dfrac{980}{1960}\\\\\Rightarrow x=0.5\ m[/tex]
Answer:
0.5
Explanation:
The burner in a hot air balloon adds 6400 J of heat to the balloon while the ballon expands. As the balloon expands, it does 3100 J of work on the surrounding air. What is the internal change in thermal energy of the balloon?
Answer:
the change in the internal energy of the balloon is 3,300 J
Explanation:
Given;
heat gained by the balloon system, Q = 6,400 J
work done on the surrounding air by the balloon, W = 3,100 J
The change in the internal energy of the system is calculated from the first law of thermodynamics;
ΔU = Q - W
where;
ΔU is the change in the internal energy of the balloon;
ΔU = 6,400 J - 3,100 J
ΔU = 3,300 J
Therefore, the change in the internal energy of the balloon is 3,300 J
Do you believe in aliens? And if so, what's your reasoning for believing in them?
Answer:
I believe in aliens but I do not think everyone should. I started to believe in aliens since the US government said they would be taking extraterrestrial life seriously. They will be in our lives sooner or later, so we shouldn't be ignoring their presence. I believe them because surveys show that nearly half of Americans believe that aliens have visited the Earth, either in the ancient past or recently. That percentage has been increasing. Belief in alien visitation is greater than belief that Bigfoot is a real creature, but less than belief that places can be haunted by spirits. Also there have been a lot of UFO sightings, and a Navy Jet has a video of that as well. These small things is just hard to ignore, and they make me and hopefully others believe in aliens.
for the equation BaCI2 + Na2SO4 > BaSO4 + 2NaCI
A. reactants: 1 ;products: 1
B. reactants: 1 ;products: 2
C. reactants: 2 ;products: 1
D. reactants: 2 ;products: 2
In the diagram, q1 = +2.00 x 10-5 C,
q2 = +3.80 x 10-6 C, and q3 = +5.30 x 10-5 C.
What is the electric potential energy, Ue, for
charge qy? Include the correct sign (+ or -).
Answer:
U = 3.59 10⁻⁹ J
Explanation:
Electric potential energy is
U = k ∑ [tex]\frac{q_iq_j }{r_i_j}[/tex]
in this case
U = k (q₁q₂ / r₁₂ + q₁q₃ / r₁₃ + q₂q₃ / r₂₃)
the distances are
r₁₂ = 1.15
r₁₃ = 1.15 +2.88 = 4.03 m
r₂₃23 = 2.88
we substitute
U = 9 109 (2 10-5 3.8 10-6 / 1.15 + 2 10-5 5.30 10-5 / 4.03 + 3.8010-6 53 010-5 / 2.88)
U = 9 109 (6.609 10-11 + 2.63 10-10 + 6.99 10-11)
U = 9 109 (39,899 10-11)
U = 3.59 10⁻⁹ J
Answer:
Q2 = 0.0346 J
Explanation:
I don't know what Q1 is but I did solve for Q2. I'm using this because no other question has been asked to solve for Q2 :)
The material that would eventually make all the major bodies in our solar system first gathered together as smaller pieces which astronomers call:
Answer:
The answer is "planetesimals".
Explanation:
The uncountable little corpses of the accreted gas and dust were supposed to orbit the Sun while the planets were formed. The theory explaining the creation of the solar system as a whole is termed the quark-gluon plasma hypothesis.
An object produced by dust, rock, and other materials is called a planetesimal. This word is rooted throughout the microscopic idea, which shows that an object is too small to observe or quantify. Everywhere from many meters to hundreds of kilometers asteroids may acquire size.
If the resistance is 25 and the voltage is 75. What is the amount of current that I will be getting?
Answer:h
Explanation:
What is this?
Picture
Answer:
may be upside down alphabet :"T"
Explanation:
explain why it is important that the Earths atmosphere absorbs gramma rays emitted by the sun
Answer:
Gamma rays have so much energy they could harm people on Earth. People are protected from gamma rays by Earth's atmosphere. The atmosphere absorbs gamma rays, preventing them from affecting life on Earth. Because gamma rays cannot penetrate Earth's atmosphere, scientists use satellites in space to study them.
Answer:
Explanation:
because gamma rays have so much energy they could harm people on earth
How much current flows in the circuit if two resistors of 6 connected in parallel are
supplied with potential difference of 12 volts?
Answer:
4 A
Explanation:
Firstly we need to calculate the equivalent resistance. Since, two resistors of 6 connected in parallel, so equivalent resistance will be given by,
[tex]\longrightarrow[/tex] 1/R = 1/R1 + 1/R2
[tex]\longrightarrow[/tex] 1/R = (1/6 + 1/6) Ω
[tex]\longrightarrow[/tex] 1/R = (1 + 1)/6 Ω
[tex]\longrightarrow[/tex] 1/R = 2/6 Ω
[tex]\longrightarrow[/tex] R = 6/2 Ω
[tex]\longrightarrow[/tex] R = 3 Ω
We know that,
[tex]\longrightarrow[/tex] V = IR
V denotes p.d (12V)I denotes currentR denotes resistance (3 Ω)[tex]\longrightarrow[/tex] 12 = I × 3
[tex]\longrightarrow[/tex] 12 ÷ 3 = I
[tex]\longrightarrow[/tex] 4 Ampere = I
why is oil denser than air
Answer:
The molecules of oil are more packed together than those of air.
Un móvil recorre una trayectoria en línea recta de 6000 metros y demora 30 minutos. ¿Cuál es su rapidez expresada en Km/h?
Answer:
La rapidez del móvil es 12 kilómetros por hora.
Explanation:
Asumamos que el móvil experimenta un movimiento rectilíneo uniforme, cuya ecuación cinemática es la siguiente:
[tex]v = \frac{x}{t}[/tex] (1)
Where:
[tex]x[/tex] - Distancia recorrida, en kilómetros.
[tex]t[/tex] - Tiempo, en horas.
[tex]v[/tex] - Rapidez, en kilómetros por hora.
Si tenemos que [tex]x = 6000\,m[/tex] y [tex]t = 30\,min[/tex], entonces la rapidez del móvil es:
[tex]v = \frac{6000\,m\times \frac{1}{1000}\,\frac{km}{m}}{30\,min \times \frac{1}{60}\,\frac{h}{min} }[/tex]
[tex]v = 12\,\frac{km}{h}[/tex]
La rapidez del móvil es 12 kilómetros por hora.
