Answer:
require a medium to propagate
Explanation:
this is because electromagnetic waves can travel through vacuum at the speed of 3.0 x 10^8 m/s
because they don't need particles to transfer energy
hope this helps
How are reversibility, time, and entropy connected
Answer:
As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system can increase, but not decrease. ... Thus, entropy measurement is a way of distinguishing the past from the future.
Explanation:
A projectile is shot horizontally from the edge of a cliff, 400 m above the ground. The projectile is traveling horizontally at 65 m/s the moment it leaves the cannon.
What is the initial vertical velocity of the projectile?
Determine the time taken by the projectile to hit the ground.
How far does the projectile land from the base of cliff?
Find the vertical component of the velocity just before the projectile hits the ground.
What is the magnitude of the final vector velocity the instant before it hits the ground?
What is the direction of the final vector velocity the instant before it hits the ground?
Answer:
a) [tex]v_{oy}[/tex] = 0, b) t = 9.035 s, c) x = 587.275 m, d) v_y = -88.54 m / s,
e) v = 109.84 m / s, f) θ = -53.7º
Explanation:
This exercise is a projectile launch
a) as the projectile is launched horizontally, its initial vertical velocity is zero
[tex]v_{oy}[/tex] = 0
b) let's use the relation
y = y₀ + v_{oy} t - ½ g t²
when reaching the ground y = 0 and the initial vertical velocity is v_{oy}=0
0 = y₀ + 0 - ½ g t²
t = [tex]\sqrt{ \frac{2 v_o}{g} }[/tex]
t = [tex]\sqrt{ \frac{ 2 \ 400 }{ 9.8} }[/tex]
t = 9.035 s
c) the horizontal distance is
x = v₀ₓ t
x = 65 9.035
x = 587.275 m
d) the vertical speed when touching the ground
v_y = [tex]v_{oy}[/tex] -gt
v_y = 0 - 9.8 9.035
v_y = -88.54 m / s
the negative sign indicates that the velocity is directed downwards
e) the velocity at this point
v = [tex]\sqrt{ v_x^2 + v_y^2}[/tex]
v = [tex]\sqrt{65^2 + 88.54^2}[/tex]
v = 109.84 m / s
f) the direction of the velocity
let's use trigonometry
tan θ = v_y / vₓ
θ = tan⁻¹1 v_y / vₓ
θ = tan⁻¹ (-88.54 / 65)
θ = -53.7º
this angle is measured clockwise
A tennis ball covers a distance of 12 meters in 0.4 seconds what is the velocity of the tennis ball?
Answer:
30m/s
Explanation:
Given parameters:
Distance = 12m
Time taken = 0.4s
Unknown:
Velocity of the tennis ball = ?
Solution:
Velocity of a body is the displacement per unit of time.
Velocity = [tex]\frac{displacement}{time}[/tex]
So;
Velocity = [tex]\frac{12}{0.4}[/tex] = 30m/s
prove that total mechanical energy is always constant
Explanation:
We know that the overall mechanical energy of a device stabilizes in the absence of any external force. We know that that the total of potential and kinetic of the freely velocity vector remains same. ,So mechanical energy of a body, underneath gravitation, remains constant.
Some one plz help me and I will give you brainliest plz
A car accelerates from 20.0 m/s to 28.0 m/s over a distance of 50.0 m. What is the car’s acceleration?
Answer:
Explanation:
[tex]V^2=V^2_o+2a(x_f-x_i)[/tex]
[tex]28^2=20^2+2a(50)\\784=400+100a\\384=100a\\a=3.84m/s^2[/tex]
A 1.5 kg block moves at 4 m/s
Answer:
12 joules
Explanation:
I'm assuming you're looking for kinetic energy?? Kinetic energy is 1/2 mv^2. 4 squared is 16, 16 times 1.5 = 24. 24/2 = 12.
A new compound has just been developed. Its formula is: C17H2ON4NaOgP.
How many different elements make up this compound?
A 8
B 7
C6
D 32
Answer:
B- 7
Explanation:
its how many elements, you don't need the amound of each element. you have to count the number of capitalized letters. Hope this helps!
which term describes when a substance is changed from a liquid to a gas
Answer:
vasporisation
Explanation:
process used to change liquid to gass
Answer:
I believe it's Evaportation or another word would be Vaporisation.
Explanation:
hope this helps! ^^
describe nucleus (animal) in your own words(20 points)
Answer:
The nucleus is a highly specialized organelle that serves as the information and administrative center of the cell. ... Most of the nuclear material consists of chromatin, the unstructured form of the cell's dna that will organize to form chromosomes during mitosis or cell division.
Explanation:
How long will it take a rocket traveling at 8km/s to reach 20 km?
Answer:
2.5 seconds
Explanation:
20:8= 2.5 seconds
have a nice day! (^o^)
Answer:
2.5 seconds
Explanation:
20 ÷ 8 = 2.5
That's it.
Which of the following is an example of an electromagnet?
A. The magnets used to lift metal or cars in a salvage/junk yard
B. the bar magnets we used in the lab
C.the magnets used to hold pictures on a refrigerator or papers on a metal filing cabinet
Answer:
A. The magnets used to lift metal or cars in a salvage/junk yard
Explanation:
An electromagnet is defined as a type of magnet which are made up of wires in coil shape. Magnetic field in these wires are produced by electric current.
An example of an electromagnet is magnets used to lift metal or cars in a salvage/junk yard because a crane is used in junkyard to lift metal in which crane is attached to a iron disc and when electricity is off, the disc move downwards and placed near required metal and switch on the electricity when disc reaches on metal or cars to be lifted. This electricity generates magnetism in the iron disc and attract metal or cars from the junkyard.
Hence, the correct answer is "A. The magnets used to lift metal or cars in a salvage/junk yard".
Find the following answer based on the image.
We are given:
Mass of Neptune = 1.03 * 10²⁶ kg
Distance from the center of Neptune (r) = 2.27 * 10⁷
now, computing the value of the acceleration due to gravity (g)
Finding g:
We know the formula:
g = G(mass of planet) / (r)²
g = [6.67 * 10⁻¹¹ * 1.03*10²⁶] / (2.27*10⁷) [since G is 6.67*10⁻¹¹]
g = (6.87 * 10¹⁵) / (5.15 * 10¹⁴)
which can be rewritten as:
g = (6.87 * 10¹⁵ * 10⁻¹⁴) / 5.15
g = (6.87 * 10¹⁵⁻¹⁴) / 5.15
g = (6.87/5.15) * 10
g = 1.34 * 10
g = 13.4 m/s² (approx)
A force of 900 N pushes a wedge 0.10 m into a log. If the work done on the log is 50 J, what is the efficiency of the wedge?
Answer:
I'm fairly certain it's 1,800
Explanation:
The efficiency of the wedge with force F=900 N displaces the wedge 0.10 m is 55.55% or 56%.
What is the efficiency of the machine?The efficiency of the machine equals the ratio of output energy and input energy. It is also defined as the ratio of work done on a load by the machine to the work done on the effort by the machine.
A load is defined as the weight lifted by the machine. The effort is defined as the force applied to bring the desired change in the load. Work done is defined as the product of force and displacement.
The efficiency, η = Output power / Input power, and the highest efficiency of the machine is equal to one. The efficiency of the machine has no unit. The efficiency η = (Actual work done / Ideal work done) × 100.
From the given,
Force = 900 N
Displacement = 0.1 m
Work done = F × s = 900×0.1 = 90 J
Actual work done = 50 J
Efficiency,η = (50/90) × 100
η = 55.55 %
Thus, the efficiency of the wedge is 55.56%.
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Plz help me plzzz. I'm begging you
Answer:
a then c then b
Explanation:
can you please explain hooks law?
Explanation:
Hooke's law is a law of physics that states that the force needed to extend or compress a spring by some distance scales linearly with respect to that distance—that is, Fₛ = kx, where k is a constant factor characteristic of the spring, and x is small compared to the total possible deformation of the spring.
Science: Work, Power and Efficiency Practice Problems:
Work = Force x Distance
Power = Work / Time
Percent Efficiency = Work
Output/Work Input x 100
Step 1: Write the equation
Step 2: Substitute with units
Step 3: Solve with units
rounding to the nearest tenth
1) It took 639 Newtons to push a table 21 meters. How much work was done?
Answer:
I believe it is 13,419 joules.
Explanation:
I could be very wrong, please fact check me
A car drives in a circle at 56 km/hr. Which of
the following accurately describes the
motion of the car? The car's -
speed and velocity are both constant.
velocity is constant but speed is changing.
speed is constant but velocity is changing.
speed and velocity are both changing.
Answer:
Speed is constant but velocity is changing
Explanation:
Speed is a scalar quantity, meaning magnitude only. Velocity is a vector quantity, meaning magnitude and direction. If you're moving in a circle at a constant speed, the speed is constant but the direction is constantly changing. Therefore, the speed is constant but velocity changes.
Please help with this question !!!!!
Answer:
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Can any one here form light from lemon?
Answer:
I did not get it
Explanation:
what u r saying
C + H2 ----------> CH4
Answer:
yes
.......................
Answer:
C + 2H2 -----> CH4
What is the mass of an object if it's gravitational potential energy is 3822 J and it is 15 m above the ground
Answer:
B. I DID IT AND GOT IT RIGHT
Explanation:
Answer:
It is B
Explanation:
i did this one
I need help immediately and thank you of if you answer the question
Answer:
c. Position C
Explanation:
As the magnetic force is the strongest at the end of the poles and it decreases when it comes to its centre.
what are the standard units of displacement?
force of 7 N acts on an object.
The displacement is, say 8 m, in
the direction of the force
(Fig. 11.3). Let us take it that the
force acts on the object through
the displacement. What is the
work done in this case?
Explanation:
Given
Force (F) = 7 N
Displacement (d) = 8 m
work done (W) = ?
We know that
W = F * d
= 7 * 8
= 56 J
The work done in this case is 56 Joule.
How might electric fields be involved in a levitation device?
Answer:
When a magnet is moving relative to a conductor in close proximity, a current is induced within the conductor. This induced current will cause an opposing magnetic field. This opposing magnetic field can be used to levitate a magnet.
Explanation:
What is kinetic energy
Answer:
Kinetic energy, form of energy that an object or a particle has by reason of its motion. ... Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass.
Credits to britannica.com
Explanation:
Hope this helps
Kinetic energy of an object is the energy that it possesses due to its motion.
Describe a way that gravity influenced the formation of the solar system, with the planets orbiting the sun.
Gravity influenced the formation of the solar system, with the planets orbiting the sun.
What is Gravitational Force ?Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,
F [tex]\alpha[/tex] m₁.m₂
F [tex]\alpha[/tex] 1/r²
F = G m₁,m₂÷r²
where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².
Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].
According to Kepler's first law of motion, every planet is moving in an elliptical orbit with sun has situated at one of the foci of the orbit.
when a planet moves in the orbit around the sun, it moves in a stable orbit. in this orbit , centripetal force is equal to centrifugal force, in this case centripetal force appears as gravitational force. Means Gravitational force between sun and planet balances the centrifugal force which is outwards. In such a way gravity influenced the formation of the solar system.
Hence gravity plays crucial role in the formation of solar system.
To know more about Gravity :
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Which is considered a dark green vegetable?
A.
Carrots
B.
Broccoli
C.
Squash
D.
Green peas
Answer:
Broccoli
Explanation:
Answer:
b. broccoli
Explanation:
took the quiz
hope this helps
What kinds of bonds make up a formula unit of sodium chloride?
a.
Ionic bonds
b.
Covalent bonds
c.
1 ionic bond and 1 covalent bond
d.
Van der Waals forces
Answer:
a.ionic bond is kinds of bonds make up a formula unit of sodium chloride.
Answer:
A
Explanation: