A rock is dropped from a cliff that is 80 m above the ground. What is the velocity of the rock when it hits the ground? (hint: acceleration due to gravity g = 9.81 m/s2)
Answer:
45.1 m/s
Explanation:
use the equation v = u + at substitute the values v = 0 + 9.8×4.6 v = 45.08 round to about 3 s.f v = 45.1 m/s I do apologize if I'm incorrect.
what two elements take up the most space in the universe
Answer:
helium and hydrogen
Explanation:
Some characteristics that are common to metals are that they are good conductors or heat and electricity , are malleable , and are often shiny (Have luster ) in which of the following groups would your expect every element to share these properties
A potassium (K) , chromium (fr) , and tellurium (Te)
B sodium (na), cobalt (Co) , and platinum (Pt)
C ruthenium (Ru) ,cooper (Cu), and radon (rn)
D oxygen (O) fluorine (F) and argon (Ar)
Answer:b
Explanation:
Figure I shows the position of the moon at local time 10:00 P. M with respect to point A on earth’s surface. Figure II shows the position of the moon 24 hours later with respect to the same place. Which phenomenon will a person at point A observe?
Answer:
A
Explanation:
i just did this on usatestprep the answer A
A gas has an initial pressure of 50kpa at a temperature of -67°c. calculate
the final pressure of this gas if its temperature is increased to 398°c at a
constant volume.
Answer:
the pressure will be 297.01 kpa
The initial velocity of a ball sent upward from the ground, is 12 m/s. What will its final velocity be before it hits the ground
O 12 m/s
0-12 m/s
0 -9.8 m/s
O 9.8 m/s
Answer:
The final velocity s 12 m/s.
For the upwards trajectory: (using the positive value of g in the downward direction)
Vf = Vi - g t = 0 where Vi is initial velocity and Vf the velocity at max height
Vf = 12 - g t = 0 t = 12 / g time to reach max height
For the downwards trajectory
Vf = Vi + g t = 0 + g t = g * 12 / g = 12 where t was found above
We know the from 2 g h = Vf^2 - Vi^2, since the height is the same in both directions, that the ball reaches the ground with at the same speed at which it was sent.
Also, conservation of energy shows that the ball must return to the ground with the speed with which was projected.
It's not D
10 Select the correct answer.
A stability ball can be used in yoga to do which of the following?
A. Provide support
В. Make a move more challenging
C. Make a move easier
D. All of the above
You are designing a pendulum clock to have a period of 1.0 s. How long should the
pendulum be?
For an accurate design of the pendulum that will match the period, the length of the pendulum clock must be 0.25 m.
Period of oscillation of simple pendulumThe period of oscillation of simple pendulum is calculated as follows;
[tex]T = 2\pi \sqrt{\frac{l}{g} }[/tex]
where;
L is the length of the pendulumg is acceleration due to gravityT is the period of the oscillationMake "L" the subject of the formula in the above equation.
[tex]\frac{T}{2\pi} = \sqrt{\frac{l}{g }} \\\\\frac{T^2}{4\pi^2} = \frac{l}{g} \\\\l = \frac{gT^2}{4\pi ^2} \\\\l = \frac{(9.8)(1)^2}{4\pi ^2} \\\\l = 0.25 \ m[/tex]
Thus, the length of the pendulum clock is 0.25 m.
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Come on! Please answer... :( WILL GIVE BRAINLYEST TO BEST ANSWER!!! PLEASE PLEASE PLEASE PLEASE ANSWER!!!
How do the potential and kinetic energy of the cart change at each point in the diagram?
Answer:
Potential -> Kinetic -> Potential ->
Explanation:
Point A is potential becuase it's stopped (its energy isn't released). Point B is where that potential energy is released and turned into Kinetic energy. And point C is where potential energy is stored again. Same with point D.
A man walks 23 km east and then
turns around and heads west for 46
km, then east for 23 km. What is his
displacement?
A) 92 km
B) 0 km
C 46 km west
D) 46 km East
Love, which can’t be observed or measured directly, is an example of a psychological construct.
Please select the best answer from the choices provided
T
F
Answer:
f
Explanation:
Light waves and sound waves have many similar behaviors, such as reflection and refraction. One behavior they do not share is
Answer:
light waves can travel in vacuum but sound waves require a medium to travel
also light waves are electromagnetic waves while sound waves are mechanical, light waves are transverse waves while sound waves are longitudinal waves
While sound waves are mechanical, light waves are electromagnetic. Unlike sound waves, which are longitudinal, light waves are transverse. Light waves can go across a vacuum. Since sound waves need a physical medium to move through, they cannot move in a vacuum.
What is sound wave?The pattern of disruption brought about by the movement of energy through a medium (such as air, water, or any other liquid or solid matter) as it spreads away from the source of the sound is known as a sound wave. Pressure waves are generated by item vibrations that cause sound waves, such as those from a ringing phone.
Unlike sound waves, which need a medium to propagate, light waves may travel in a vacuum.
Additionally, light waves are transverse waves whereas sound waves are longitudinal waves and light waves are electromagnetic waves.
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A car is moving from rest and attained a velocity of 80 m/s. Calculate the acceleration of the car after 5 s?
Answer:
400 m/s
Explanation:
If it is moving at a velocity of 80 m/s from rest, then after 5 s it would be at 400 m/s.
80 x 5 = 400
why acceleration is a derived unit?
The acceleration is derived from the some other quantities like change in velocity / time take . If we see carefully that formula of acceleration you find that it is basically derived from fundamental quantities therefore acceleration is called a derived quantities.
what are the invisible forces of nature
Answer:
Gravity, Friction, Air resistance, magnetism, static electricity
Explanation:
Answer:
gravity friction air resistant are a few
Which mathematically describes the wave properties of electrons?.
Answer:
On Waves. Quantum mechanically, an electron can be described by a wave function oscillating in space and time that has mean values equal to the expectation values of observables corresponding to given operators. ... Electrons are fermions. They are charged particles. in short the quantum theory
i hope its helpful !
Dennis the Menace uses his slingshot to shoot a small rock at his neighbor's flowerpots. The rock travels a distance of 12.5 cm from the point at which he pulls it back to the point at which it leaves the slingshot. It leaves the slingshot at a velocity of 6.24 m/s. Find the average acceleration of the rock.
Answer:
[tex]a=155.750\ m/s^2[/tex]
Explanation:
It is given that,
A small rock is shoot at Dennis' neighbor's flowerpots. The rock travels a distance of 12.5 cm from the point at which he pulls it back to the point at which it leaves the slingshot.
Final velocity of the rock, v = 6.24 m/s
The initial velocity of the rock, u = 0 (as it was at rest)
Let a is the acceleration of the rock. It can be calculated using the equation of kinematics as follows :
[tex]v^2-u^2=2ad\\\\\text{Put u = 0 }\\\\v^2=2ad\\\\a=\dfrac{v^2}{2d}\\\\a=\dfrac{(6.24)^2}{2\times 12.5\times 10^{-2}}\\\\a=155.750\ m/s^2[/tex]
So, the average acceleration of the rock is [tex]155.750\ m/s^2[/tex].
What is meant by solenoid? How does a current carrying solenoid behave?
•Question⟿What is meant by solenoid?
•Answer⟿If a conducting wire is wound in form of a cylindrical coil whose diameter is less in comparison to its length, the coil is called a solenoid. It looks like a helical spring.
•Question⟿How does a current carrying solenoid behave?
•Answer⟿
The magnetic field lines of a current carrying solenoid are similar to the magnetic field lines of a bar magnet. Thus, a current carrying solenoid behaves just like a bar magnet.A current carrying solenoid when suspended freely sets itself in the north south direction exactly in the same manner as a bar magnet does.A current carrying solenoid also acquires that attractive property of a magnet. If iron fillings are brought near the current carrying solenoid, it attracts them.Explanation:
Hope it helps you!!
current carrying solenoid behaves as an electromagnet. The uniform magnetic field inside it may magnetise a steel rod permanently. Detailed Answer: A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a Solenoid.
hope it helps you :)
A cannon is fired horizontally at 243 m/s off of a 62 meter tall, shear vertical cliff. How
many seconds will have elapsed before the cannon ball strikes the ground?
Horizontal component of ball, u = 0 m/s.
Height from which it thrown, h = 62 m.
By equation of motion :
[tex]s=ut+\dfrac{at^2}{2}[/tex]
Putting all given equation, we get :
[tex]62=0\times t+\dfrac{10t^2}{2}\\\\t=\sqrt{12.4}\ s\\\\t = 3.52\ s[/tex]
Therefore, time taken is 3.52 s.
Hence, this is the required solution.
An emission spectrum is: various wavelengths emitted by an excited substance the wavelengths that are removed from a continuous spectrum when it passes through a substance a spectrum that contains only a few discrete wavelengths a spectrum containing all wavelengths the range of wavelengths emitted or absorbed by an object
Answer: Various wavelengths emitted by an excited substance
Explanation:
What indicates that an area in the Northern Hemisphere is experiencing summer?
O The Sun is at its lowest point in the sky,
O The Sun is directly over Earth's north end,
The Northern Hemisphere receives fewer direct rays from the Sun.
The northern end of Earth's axis is tilted away from the Sun.
Answer:
b
Explanation:
Answer:
its b, the sun is directly over earths north end
Explanation:
Which events may occur when ocean salinity increases? check all that apply. mass of water increases freezing point of water decreases sunlight in deeper locations decreases buoyancy of objects in the water increases amount of dissolved gases in water increases
The mass of water increases, the freezing point of water decreases. and the buoyancy of objects in the water increases may occur when the ocean sanity increases.
What is ocean sanity?Seawater is salty due to a variety of substances. The majority of them arrive via rivers, which bring chemicals dissolved from rock and soil. The most common is sodium chloride, also known as salt.
The most popular approach to quantify salinity is to count the amount of salt in 1,000 g of water, which is referred to as ppt. The majority of the ocean has a salinity of 34 to 36 parts per thousand.
Salinity makes water colder and denser by lowering its temperature. The chilly water sinks to the ocean's depths. Slow currents carry it throughout the marine basins.
Because the items have a lower density, they flow across the water's surface. As a result, the buoyancy of items in water improves.
So the events that may occur when ocean salinity increases will be;
1)The mass of water increases.
2) Freezing point of water decreases.
3) buoyancy of objects in the water increases.
Hence the masses of water increase, the freezing point of water decreases. and the buoyancy of objects in the water increases may occur when the ocean sanity increases.
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what is a joule in science? and how does it relate to work? helppp I need an answer!!! (no links)
Answer: joule, unit of work or energy in the International System of Units (SI); it is equal to the work done by a force of one newton acting through one metre.
Explanation:
This is a unit used to measure energy or work. One joule is the amount of energy required to produce one watt of power for one second. It's also the work done by a force equal to one newton exerted over a distance of one meter.
Hope this helps!
A man who weights 900N stands on a platform scale in a elevator. The elevator has a mass of 4000kg; the reading scale is 700N. What is the direction of the net force acting in the man
Hi there!
We know that there are TWO forces acting on the man.
Force due to gravity: Acts DOWNWARDNormal force due to the elevator floor: UPWARDWe can express this in an equation. Let DOWN be NEGATIVE, and UP be POSITIVE.
[tex]F_{net} = N - F_g[/tex]
Recall that a SCALE measures the NORMAL FORCE, NOT the WEIGHT. Therefore:
N = 700 N
W = 900 N
[tex]F_{net} = 700 - 900 \\\\F_{net} = -200N[/tex]
Since downward is negative, the net force is acting DOWNWARD.
Which is a convex lens? (The blue arrows represent the direction of light as it interacts with the lenses. ).
Image C is a convex lens.An optical lens is made up of two spherical surfaces is convex lens.Its surfaces are curved outwards.
What is convex lens ?An optical lens is made up of two spherical surfaces is convex lens The lens is called a biconvex lens or simply convex lens if those surfaces are curved outwards.
Converging lens is another name for it. It's because it brings all the light rays that are parallel to the primary axis together at the focus point (F).
The picture created by a convex lens is always real and inverted. The produced image is virtual and erect when the item is positioned between the focus and the optical center of the lens.
Hence image C is a convex lens.
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Answer:
C
Explanation:
What is the correct definition of acceleration?
a) the change of velocity over time
b) the change of inertia over time
c) the change of velocity over distance
d) the change of speed over time
Answer:
Hello
a) the change of velocity over time
Answer:
c.the change of velocity over distance
Thermal energy is the_____
energy of particles in an object.
Answer:
sum of the kinetic and potential energy
Explanation:
The dehydration butanol on alumina is carried out over a silica-alumina catalyst at 680 K.
CH3CH2CH2OH →CH3CH = CHCH3 + H2O
The rate law iswith k = 0. 054 mol/gcat·h·atm and KBu = 0. 32 atm^–1. Pure butanol enters a thin-tubed, packed-bed reactor at a molar flow rate of 50 kmol/hr and a pressure of 10 atm (1013·kPa).
Required:
a. What PBR catalyst weight is necessary to achieve 80% conversion in the absence of pressure drop?
b. What "fluidized CSTR" catalyst weight is necessary to achieve 80% conversio?
A) The PBR catalyst weight that is required to achieve 80% conversion in the absence of pressure drop is : 370 mg
B) The fluidized CSTR catalyst weight necessary to achieve 80% conversion is : 995.025 g
A) Determine the PBR catalyst weightTo calculate the PBR catalyst weight required to achieve 80% conversion in the absence of pressure drop we will apply the equation below
w = [tex]\frac{V_{o} }{KC_{ao}(1/x - 1 ) }[/tex] ---- ( 1 )
insert values into equation ( 1 )
w = [tex]\frac{50 kmol}{0.54 * 10 (\frac{1}{0.8}) * 1 }[/tex]
PBR catalyst weight ( w ) = 370 mg
B) Determine the fluidized CSTR catalyst weight necessary to achieve 80% conversion
applying the equation below
W = [tex]\frac{Fbwx}{-r'Bu}[/tex]
= [tex]\frac{50kmol/r * 0.8}{0.042mol/gcat.h}[/tex]
= 995.025 gcat
Hence we can conclude that The PBR catalyst weight that is required to achieve 80% conversion in the absence of pressure drop is : 370 mg The fluidized CSTR catalyst weight necessary to achieve 80% conversion is : 995.025 g.
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How many oxygen (O) atoms are in a molecule of Cg H,O3?
A. 1
B. 3
C. 10
D. 4
Answer:
B. 3
Explanation:
(e) The National Grid supplied a house with 18 000 000 J of energy. in 1 hour. What was the average current supplied to the house during that hour? Write any equations that you use.
Answer:
Explanation:
4.0/5
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Electrical power = (voltage) x (current)
Electrical energy = (power) x (time)
Combine those definitions:
Energy = (voltage) x (current) x (time)
Divide each side by (voltage x time), and we have
Current = Energy / (voltage x time)
You told us that
Energy = 1.8 x 10⁷ joules
Time = 1 hour = 3,600 seconds
so we have
Current = (1.8 x 10⁷) / (voltage x 3,600).
If you live in the US, Canada, or Mexico, your voltage is 120 volts.
Current = (1.8 x 10⁷) / (120 x 3,600) = 41-2/3 Amperes
If you live practically anywhere else in the world, your voltage is 240 volts.
Current = (1.8 x 10⁷) / (240 x 3,600) = 20-5/6 Amperes.