Answer:
The type of image formed on a screen by a convex lens is real, enlarged and inverted.
Explanation:
A lens can be defined as a transparent optical instrument that refracts rays of light to produce a real image.
Basically, there are two (2) main types of lens and these includes;
I. Diverging (concave) lens.
II. Converging (convex) lens.
A converging lens refers to a type of lens that typically causes parallel rays of light with respect to its principal axis to come to a focus (converge) and form a real image.
Basically, the type of image formed on a screen by a converging (convex) lens is real, enlarged and inverted because it is usually thick across the middle (causing rays of light to converge) but thin at the lower and upper edges.
Mike is serving the volleyball for the second time in a volleyball game. If the ball leaves his hand with twice the velocity it had on the first serve, its horizontal range R would be:
Answer:
His new horizontal range is 4 times his initial range.
Explanation:
Since Mike serves the ball with velocity, u, his horizontal range is
R = u²sin2Ф/g where Ф is the angle between u and the horizontal.
Now, if on his second serve, the ball leaves his hand with twice the velocity of his initial serve, the new velocity is v = 2u.
So, the new range R' = v²sin2Ф/g
R' = (2u)²sin2Ф/g
R' = 4u²sin2Ф/g
Since R = u²sin2Ф/g,
R' = 4u²sin2Ф/g
R' = 4R
So, his new horizontal range is 4 times his initial range.
why is oil denser than air
Answer:
The molecules of oil are more packed together than those of air.
show that pv=nrt has the same unit with energy
Answer:
The unit of the equation P·V = n·R·T is the Joules which is the same as the unit of energy
Explanation:
The unit of energy is Joules, with symbol J
The given equation for an ideal gas is P·V = n·R·T
Where;
P = The pressure of the gas with units Pascals, Pa
V = The volume of the gas, with units m³
n = The number of moles with unit moles
R = The universal gas constant = 8.314 J/(mol·K)
T = The temperature, with units, Kelvin, K
Therefore, we get;
P·V has unit 1 Pa × 1 m³ = 1 N/m² × 1 m³ = 1 N·m = 1 Joule
Similarly, we get
n·R·T with units n mole × 8.314 J/(mol·K) × 1 K = 8.314·n Joules
Therefore, P·V = n·R·T, has the unit of Joules which is the same unit with energy.
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
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
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.
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 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 ball is thrown vertically upward. As it rises, what happens to its potential energy?
Answer:
Explanation:
As the ball rises, its PE increases because the potential energy is equal to the mass of the ball times gravity times the height of the ball. The higher the height, the higher the PE.
Answer:
According to the law of conservation of energy its kinetic energy is getting converted in to potential energy because of gain in height. So, if the velocity of a ball goes on decreasing when it is thrown vertically upwards. When its velocity becomes zero, its potential energy becomes maximum.
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
A 1.25 kg block is attached to a spring with spring constant 17.0 N/m . While the block is sitting at rest, a student hits it with a hammer and almost instantaneously gives it a speed of 49.0 cm/s . What are You may want to review (Pages 400 - 401) . Part A The amplitude of the subsequent oscillations
Answer:
The amplitude of the subsequent oscillations is 13.3 cm
Explanation:
Given;
mass of the block, m = 1.25 kg
spring constant, k = 17 N/m
speed of the block, v = 49 cm/s = 0.49 m/s
To determine the amplitude of the oscillation.
Apply the principle of conservation of energy;
maximum kinetic energy of the stone when hit = maximum potential energy of spring when displaced
[tex]K.E_{max} = U_{max}\\\\\frac{1}{2} mv^2 = \frac{1}{2} kA^2\\\\where;\\\\A \ is \ the \ maximum \ displacement = amplitude \\\\mv^2 = kA^2\\\\A^2 = \frac{mv^2}{k} \\\\A = \sqrt{\frac{mv^2}{k}} \\\\A = \sqrt{\frac{1.25\ \times \ 0.49^2}{17}} \\\\A = 0.133 \ m\\\\A = 13.3 \ cm[/tex]
Therefore, the amplitude of the subsequent oscillations is 13.3 cm
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]
Mars is about 1.5 times further from the Sun than Earth. Compared to Sun as seen from Earth, the Sun as seen on Mars is
Answer:
The Sun on Mars appears two third of the size of the Sun as seen Earth
Explanation:
The distance from the Sun to Mars = 1.5 × The distance from the Sun to Earth
Therefore, compared to the Sun as seen on Earth, we have;
The Sun as seen on Mars = 1.5 × smaller than the Sun as seen on Earth = 2/3 × The size of the Sun as seen on Earth
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.
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
at which point is the Kinetic energy the lowest?
Answer:
the lowest kinetic energy point is option D
If the resistance is 25 and the voltage is 75. What is the amount of current that I will be getting?
Answer:h
Explanation:
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
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
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!!
What do you think Jose’s grandmother meant by saying that the bread was too dense? What other things can you think of that are “dense”?
Answer:
What I think that Jose's grandmother meant by saying that the bread was too dense is that she thinks the bread is too heavy or it can even mean to be too compacted in substance. The matter in the bread are close together and not spread out like in the air, when the matter in the air starts to come closer together it starts to make fog, because it is becoming more dense. Some more things that are heavy or dense are things like a big stereo speaker, an anvil, or even a big piece of wood used to build.
Explanation:
help helphelp it is 90km per hr
Answer:
Explanation:
The equation for acceleration is
[tex]a=\frac{v_f-v_0}{t}[/tex] which is the final velocity minus the initial velocity divided by the time. I first need to put the units all in the same terms. We have the velocity given as km/hr, but the time is given in seconds and that's not gonna work. I will change the velocity to km/sec:
[tex]90\frac{km}{hr}*\frac{1hr}{3600s}=.025\frac{km}{s}[/tex] That's the value we will use for the final velocity of this car in the equation for acceleration:
[tex]a=\frac{.025-0}{10}=.0025\frac{km}{s^2}[/tex]
The second part of this problem asks how far the car travels in this 10 seconds. We just determined that the car can travel .025 km in 1 second, so in 10 seconds the car travels 10(.025) = .25 km
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
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
An athlete runs around a circular track of radius 50 m and finishes at the same point where he began his journey. His total displacement in metre(s) is evaluated to be
Answer:
Explanation:
His displacement is 0 because he ended up exactly where he started.
Fluorometers are designed so that the path of the excitation light is at a right angle to the path of the emitted light. What is the purpose of this design
Answer: prevent excitation light from reaching the detector
Explanation:
A fluorometer refers to the device that's used in the measurement of parameters that are of visible spectrum fluorescence. They also prevent excitation light from reaching the detector.
These parameters are used in the identification of the amount and presence of molecules in a medium.
An emergency relief plane is dropping a care package from a plane to a group of medical personnel working for a relief agency in an African village. The package is designed to land in a small lake, inflate an attached raft upon impact, and finally resurface with the raft side down. The plane will be moving horizontally with a ground speed of 59.1 m/s. The package will be dropped a horizontal distance of 521 m from the intended target location. At what altitude above the pond must the plane be flying in order to successfully accomplish this feat?
Answer:
The altitude of the plane is 379.5 m.
Explanation:
Initial horizontal velocity, u = 59.1 m/s
Horizontal distance, d = 521 m
let the time taken by the packet to cover the distance is t.
Horizontal distance = horizontal velocity x time
521 = 59.1 x t
t = 8.8 s
let the vertical height is h .
Use second equation of motion in vertical direction.
[tex]h = u t + 0.5 gt^2\\\\h = 0 + 4.9 \times 8.8\times8.8\\\\h= 379.5 m[/tex]
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]
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.
