Answer:
v / √2
Explanation:
A blocked from rest at the top of a hill of height h it there is negligible friction between the block and the hill, the block arrives at the bottom of the hill with speed. The block is released from rest at the top of another hill with a rough surface and height h. if one-half of the initial mechanical energy of the block Earth System is lost due to friction as the block descends the hill, the block will reach the bottom of the hill with a speed of?
Solution:
For the first block block, its potential energy at the top of the hill when it is at rest is converted to kinetic energy after release with a velocity v.
The kinetic energy = (1/2)mv², where m is the mass of the block.
For the other block placed on the top of the rough hill, the mechanical energy (kinetic energy) is halved due to the roughness of the hill. If u is the speed of this block at the bottom of the hill then:
kinetic energy of block on the rough hill = (1//2)mu²
Hence:
(1//2)mu² = half of main system kinetic energy
(1//2)mu² = 1/2 * (1/2)mv²
mu² = (1/2)mv²
u² = (1/2)v²
u = √(v²/2)
u = v / √2
Hence the speed at the bottom of the rock of the block placed on the rough surface is v / √2
3)
Which type of current in a circuit will produce a magnetic field?
a) direct current only
b) alternating current only
c) both direct and alternating current
d) Neither direct and alternating current
c) both direct and alternating current
Because Ampere's Law, a magnetic field is produced whenever an electrical charge is in motion. So, both kind of currents produces a magnetic field when electrical current is flowing through a wire.
Sally's mass on Earth is 50 kg. What is her weight on the
moon?
Answer:81.66667 N
Explanation:
Answer:
D) 81.6667
Explanation:
It is right
Brainliest? plz
The gravitational force between two objects is
proportional to the products of the masses and
proportional to the square of the distance between them.
The complete question is;
The gravitational force between two objects is ______ proportional to the products of the masses and _______ proportional to the square of the distance between them.
Answer:
First dash is directly
Second dash is inversely
Explanation:
From Newton's law of gravitation the gravitational force is given by the equation;
F = GMm/r²
Where:
F is gravitational force
M and m are two masses representing the two objects
r is the distance between them
G = universal gravitational constant
Thus, if we are to write it in proportion format, we will have;
F ∝ Mm/r²
From this proportion relationship, we can see that the Gravitational force is directly proportional to the products of the two masses and inversely proportional to the square of the distance between them.
Answer:
DirectlyInverselyExplanation:
The gravitational force between two objects is directly proportional to the products of the masses and inversely proportional to the square of the distance between them.
A teacher opens a window on a cold day. Which statement explains why the room starts to feel cooler? (1 point)
0 Air moves from the areas of higher temperature to areas of lower temperature
O Cold air is moving into the room from outside.
0 The density of the air is lower on the inside than on the outside
0 The kinetic energy of the air molecules outside is higher than the kinetic energy of the air molecules inside.
Answer:
Air moves from the areas of higher temperature to areas of lower temperature.
Explanation:
this is because hotter temperatures seek out colder temps.
hope this helped!
When a teacher opens a window on a cold day. the room starts to feel cooler because air moves from the areas of higher temperature to areas of lower temperature.
What is convection of heat transfer?The transfer of heat between two bodies by currents of moving gas or fluid is known as convective heat transfer. In free convection, air or water rises and is replaced by a cooler parcel of air or water as it moves away from the hot body.
As air moves from the areas of higher temperature to areas of lower temperature, when the teacher opens a window on a cold day, the air in the room moves out side and cold air takes the position inside the room. So, it feels cooler then.
To find more about convection, refer the link:
https://brainly.com/question/16635311
#SPJ5
Will mark brainiest!!!
1. A __ is caused by a sudden shift in the ocean crust which displaces the water. *
2. A tsunamis is possible, but unlikely at a __ plate boundary where two plates are moving sideways past each other. *
3. A Shallow __ is a good indicator of tsunamis, but sends data very slowly and cannot detect earthquakes. *
4. Tsunamis are common at __ plate boundaries, since large earthquakes release the built up pressure, resulting in a quick vertical movement of the plate. *
5. The Indonesian Earthquake of 2004 had a 9.1__, which was the third largest ever recorded in human history. *
All possible answers:
A. Earthquake
B. Tsunami
C. Magnitude
D. Sensor
E. Transform
F. Convergent
G. Divergent
Answer:
1. Tsunami
2.Divergent
3.Sensor
4.Convergent
5.Magnitude
Explanation:
What forces are acting upon a book sitting
on a
countertop?
What type of energy is stored in a pendulum at the top of its arc?
Answer:
potential
Explanation:At this point the energy is stored in a form called potential energy. This means that the system has the potential to do work or to become active thanks here to the weight's position high above the lowest point of its swing.
Scientists are studying a group of living cells under a microscope. They write down notes about the size, shape, and color of the cells as well as other traits.
Which best describes this type of investigation?
A: comparative, because the scientists will be making observations in order to form a hypothesis
B: comparative, because the scientists are measuring dependent and independent variables
C: descriptive, because the scientists are using independent variables to test a hypothesis
D: descriptive, because the scientists are writing down observations but not making comparisons
Answer:
D
Explanation:
descriptive, because scientists are writing down the observations but not making comparisons.
What is the velocity of the rock after 3.00 seconds (the rock is falling from a cliff)
Answer:
29.4 m/s
Explanation:
Using the formula: V=Vi + g.t
where V: final velocity, this is what you want.
Vi: initial velocity, equals to zero as it is falling from rest.
g: acceleration due to gravity = 9.8
t: time, which equals 3 sec.
How should the amount of elastic potential energy when the spring is fully stretched compare to the amount of kinetic energy when the spring is relaxed?
If there are no dissipative forces acting on the string, than the principle of conservation of energy holds.
When the string is relaxed, it has zero elastic potential energy
If we were strech the she spring, we would increase it's potential energy. After releasing the spring, when it's relaxed again, all potential energy will have been converted into kinetic energy.
Therefore, the elastic potential energy of the stretched spring should be equal to the amount of kinetic energy when it's relaxed
A chemical reaction is not permanent and can easily be changed back.
Group of answer choices
True
False
Answer:
I think the answer is False.
Explanation:
Because many chemical reaction are non reversible change. This means they are permanent change and cannot be undone. You cannot turn the new material made back into the original material again.
3. If I run 150m in 30 seconds, what speed will I have been running at?
Answer:
speed = distance/time
Explanation:
speed = 150/30
speed =5m/s
you were running fast .....5m/s is a good speed
A fish that lives near the surface of the ocean most likely has a swim bladder (or a body cavity) that is full of
Answer:
A fish that lives near the surface of the ocean most likely has a swim bladder (or body cavity) that is full of oxygen
Explanation:
The swim bladder is the organ present in the majority of bony fishes that provides buoyancy. The swim bladder is a bladder filled with oxygen and found in the in the body of the fish
The function of the swim bladder is to provide adequate ballast or hydrostatic balance to enable a fish to keep to a certain depth in a body of water thereby the fish does not float to the surface or sinks further
The swim bladder is also used as a sound communicating organ.
An air bubble released by a deep-water diver, 115 m below the surface of a lake, has a volume of 1.60 cm3. The surface of the lake is at sea level, and the density of the lake water can be approximated as that of pure water. As the bubble rises to the surface, the temperature of the water and the number of air molecules in the bubble can each be approximated as constant. Find the volume (in cm3) of the bubble just before it pops at the surface of the lake.
___ cm3.
Answer:
The value is [tex]V_2 = 1.9396 *10^{-5} \ m^3 [/tex]
Explanation:
From the question we are told that
The depth at which the bubble is released is [tex]h = 115 \ m[/tex]
The volume of the air bubble is [tex]V = 1.60 cm^3 = 1.60 *10^{-6} \ m^3[/tex]
Generally from the ideal gas law
[tex]PV = nRT[/tex]
Given that n , R , T are constant we have that
[tex]PV = constant[/tex]
So
[tex]P_1 V_1=P_2 V_2[/tex]
Here [tex]P_1[/tex] is the pressure of the bubble at the depth where it is released which i mathematically represented as
[tex]P_1 = P_a + P[/tex]
Here [tex]P_a[/tex] is the atmospheric pressure with value [tex]P_a = 101325 \ Pa[/tex]
and [tex]P[/tex] is the pressure due to the depth which is mathematically represented as
[tex]P = \rho * g * h[/tex]
So
[tex]P = 1000 * 9.8*115[/tex]
=> [tex]P = 1127000\ Pa[/tex]
Here [tex]\rho[/tex] is the density of pure water with value [tex]\rho = 1000 \ kg/m^3[/tex]
[tex]g = 9.8 \ m/s^2[/tex]
[tex]V_1[/tex] is the volume of the bubble at the depth where it is released
[tex]P_2[/tex] is the pressure of the bubble at the surface which is equivalent to the atmospheric temperature
[tex]V_2[/tex] is the volume of the bubble at the surface
So
[tex]V_2 = \frac{ P_1 * V_1}{ P_2}[/tex]
=> [tex]V_2 = \frac{(Pa+ P) * V_1}{P_a}[/tex]
=> [tex]V_2 = \frac{101325 + 1127000 * (1.60 *10^{-6})}{ 101325 }[/tex]
=> [tex]V_2 = 1.9396 *10^{-5} \ m^3 [/tex]
Friction is the __ __ __ __ __ between two __ __ __ __ __ __ __ __ objects. It can __ __ __ __ things down or make things stand __ __ __ __ __ .
Answer:
force ; connected ; slow ; slipping.
Explanation:
Friction is the force that occurs when two objects are in contact and they oppose relative motion of the two surfaces. The frictional forces always tries to oppose the relative motion between two objects. It makes the things to move slowly or slow down the speed by opposing its relative motion. It avoids slipping of any objects which makes objects stands slipping.
Which of the following equations accurately defines acceleration?
Plz help ASAP
Answer:
Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt. This allows you to measure how fast velocity changes in meters per second squared (m/s^2). Acceleration is also a vector quantity, so it includes both magnitude and direction.
Explanation:
Answer: i think its b
sorry if im wrong
Explanation:
Circular motion requires the application of a constant force in which direction?
Outward from the circle
Toward the center of the circle
Toward the object in motion
Away from an object
Arysha enjoys playing lacrosse on the school team. Suppose Arysha throws a lacrosse ball with a force of 6 N, and the resulting acceleration is 43 m/s2. What is the mass of the lacrosse ball?
0.14 kg
0.14 m
O 7.2 kg
258 kg
Answer:
[tex]Mass = 0.14kg[/tex]
Explanation:
Given
[tex]Force = 6N[/tex]
[tex]Acceleration = 43m/s^2[/tex]
Required
Determine the mass of the ball
This question will be answered using Newton's second law of motion.
Which states that
[tex]Force = Mass * Acceleration[/tex]
Substitute values for Force and Acceleration
[tex]6N = Mass * 43m/s^2[/tex]
Make Mass the subject
[tex]Mass = \frac{6N}{43m/s^2}[/tex]
[tex]Mass = 0.13953488372[/tex]
[tex]Mass = 0.14kg[/tex] --- (approximated)
Answer:
The answer is .14 kg
a lift travelling up to the top floor of the empire state building with a mass of 4200kg and a kenetic energy of 4116 J
Though the question does not ask for anything, I'll assume you need to calculate the speed of the lift.
Answer:
The lift travels at 1.4 m/s
Explanation:
Kinetic Energy
Is the type of energy of an object due to its state of motion. It's proportional to the square of the speed and the mass.
The equation for the kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]
Where:
m = mass of the object
v = speed at which the object moves
The kinetic energy is usually expressed in Joules (J)
If we already know the value of the kinetic energy, we can find the speed by solving for v:
[tex]\displaystyle v=\sqrt{\frac{2K}{m}}[/tex]
The lift has a mass of m=4200 Kg and has a kinetic energy of K=4116 J, thus it's moving at a speed of:
[tex]\displaystyle v=\sqrt{\frac{2*4116}{4200}}[/tex]
[tex]\displaystyle v=\sqrt{1.96}[/tex]
v = 1.4 m/s
The lift travels at 1.4 m/s
I’ll give u BRAINLIEST PLEASE!! HURRY
Answer:
C
Explanation:
A rock falls off the edge of a building and falls for 10 seconds. What was
the rock's final velocity?
A 3900 kg truck is moving at 6.0 m/s what is the kinetic energy
Answer:
70200J
Explanation:
k.E = 1/2mv^2
K.E = 1/2(3900)(6)^2
When 560,000 is written in scientific notation, what is the power of 10?
Answer: 10^5
Explanation:
Sally's mass on Earth is 50 kg. What is her weight on Earth?
Answer490N:
Explanation:
How does the Colorado river enrich the lives of millions of people ?
Answer:
This is FRESH AIR. I'm Terry Gross. Loud concerts, power tools, construction work - they're affecting people's hearing. Hearing loss isn't just a problem for older people. In a few minutes, we're going to talk about some of the new high-tech ways of dealing with it. That's the subject of the latest New Yorker article by my guest, David Owen, who is a staff writer for the magazine. He's also a contributing editor at Golf Digest, which is how he got to play golf with Donald Trump. We'll talk about that, too.
But we're going to start with the subject of Owen's new book, "Where The Water Goes," about the Colorado River. The river and its tributaries supply water to over 36 million people in seven states - Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California - and irrigates close to 6 million acres of farmland. Owen writes about the engineering feats that make all that possible and the legal and environmental battles surrounding the river. The Colorado River is so overtaxed that by the time it reaches the U.S.-Mexico border it's dry.
David Owen, welcome to FRESH AIR. So can you give us a kind of overview sense of the manmade things that have been done to control and disseminate water from the Colorado through the West?
DAVID OWEN: When you look at the Colorado River, it's not a big river. It's done these amazing things. It carved the Grand Canyon. But it's not - it's not broad. It's not like the Mississippi. The Mississippi is 1,000 miles longer, and the entire annual flow of the Colorado River flows down the Mississippi every couple of weeks. And yet in the western United States, it's incredibly important, in seven states. It supplies water to something like 26 million people. It irrigates 6 million acres of agriculture. And most of those 6 million acres are land that the river itself deposited, silt from, you know, what's missing from the Grand Canyon. It spread out across Arizona and California.
So there's this enormous network of canals and irrigation ditches and tunnels that draw water from that river and take it in some cases hundreds of miles away, you know, 300 miles to the west to Los Angeles, you know, 300 miles to the east to Phoenix and Tucson, hundreds of miles across deserts into reservoirs and canal systems. And it's governed by its own - its own laws that determine who gets to pull that water and use it and what they get to use it for.
GROSS: The plan for dividing the water among the seven river states - Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, California - that was written up in 1922. You seem to think it's a pretty bad agreement. What makes it so bad?
OWEN: Everybody thinks it's both a bad agreement and a good agreement. It's bad because it divided up the river at a time when people thought the river contained a lot more water than it actually does. It's one of these great sort of ironies of history that in the 19 - the 1920s were some of the wettest years in that part of the country since the 1400s. So the river at that time was carrying more water than ever. And so when the states divided up the river, they were dividing up - actually water that didn't exist. On the other side, the good side is that, well, it's almost a century later and that compact, the agreement among those states, still exists.
GROSS: So how has the world and how has the population in the West changed since 1922 in ways that might make that agreement kind of out-of-date?
OWEN: Well, in lots of ways. There are many more people than anybody imagined in 1922. Some of the biggest, fastest-growing cities in the country are cities that depend on water from that river. Some of the most productive agricultural land draws water from that river. You know, for a long time the fact that they had divided up water that wasn't there didn't make any difference because nobody figured out how to use up all the water anyway. But now we've gotten much better at it and we use it up. So we stretch it farther than people did in those days.
Lol I worked so hard
Hope this helped you (and its not too long...!)
Sorry if its way longer than you'd expected
define unit aland how many types of unit are there . Name them?
Answer:
7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)
Explanation:
7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)
Engine 1 produces twice the power of engine 2.
If it takes engine 1 the time T to do the work W, how long does it take engine 2 to do the same work?
Express your answer in terms of some of all of the variables T and W.
T2=________________
Answer:
[tex]T_2=\frac{T}{2}[/tex]
Explanation:
Given that engine 1 produces twice the power of engine 2.
Let [tex]P_1[/tex] and [tex]P_2[/tex] be the power of engine 1 and engine2.
So, the power of the engine 2,
[tex]P_2 = 2P_1\cdots(i)[/tex]
As, Work = Power x time,
So, the work, W, done by an engine 1:
[tex]W=P_1\timesT\cdots(ii)[/tex]
The work, W, done by an engine 2:
[tex]W_2=P_2\times T_2\cdots(iii)[/tex]
If the work done by both the engines are the same, then
[tex]W_2=W[/tex]
[tex]\Rightarrow P_2\times T_2=P_1\timesT[/tex] [from (ii) nd (iii)]
[tex]\Rightarrow 2P_1\times T_2=P_1\timesT[/tex] [by using (i)]
[tex]\Rightarrow 2 T_2=T \\\\\Rightarrow T_2=\frac{T}{2}[/tex]
Hence, [tex]T_2=\frac{T}{2}.[/tex]
The time taken for engine 2 to do the same amount of work is given by:
T₂ = 2TLet the power of the 1st engine be P₁
Let the power of the 2nd engine be P₂
Power = Work / timeFrom the question given above,
Engine 1 produces twice the power of engine 2.
Thus,
P₁ = 2P₂
P₂ = ½P₁
Next, we shall determine the power used by engine 1 to do the work in time T.Work = W
Time (T₁) = T
Power (P₁) =?Power = Work / time
[tex]P_{1} = \frac{W}{T}\\\\[/tex]Finally, we shall determine the time taken for engine 2 to do the same work.Work = W
Power of engine 1 (P₁) = [tex]\frac{W}{T}\\\\[/tex]
Power of engine 2 (P₂) = ½P₁
Power of engine 2 (P₂) = [tex]\frac{1}{2} (\frac{W}{T}) = \frac{W}{2T}[/tex]
Time (T₂) =?[tex]Power = \frac{Work}{time} \\\\ P_{2} = \frac{W}{T_{2}} \\\\\frac{W}{2T} = \frac{W}{T_{2}} \\\\\frac{1}{2T} = \frac{1}{T_{2}}\\\\[/tex]
Invert
T₂ = 2TTherefore, the time taken for engine 2 to do the same amount of work is: T₂ = 2T
Learn more: https://brainly.com/question/21822614
how do you balance Na+O2 = Na2O
Answer:
4Na + O2 → 2Na2O
Mary and Carl drove to the store to shop Their trip to the store time at the store and trip home is graphed here. What was their
Average speed for the entire trip
A) 15 km/h
B)30 km/h
C) 60 km/h
D) cannot tell from this data
Answer:
Option B. 30 Km/h
Explanation:
To solve this question, we must know the meaning of average speed.
Average speed is simply defined as the total distance travelled divided by the total time taken to cover the distance. Mathematically, it is expressed as:
Average speed = Tota distance /Total time
Thus, with the above formula, we can obtain the average speed of the entire trip as shown below:
Total distance = 60 Km
Total time = 2 h
Average speed = Total distance /Total time
Average speed = 60 /2
Average speed = 30 Km/h
Thus, the average speed of the entire trip is 30 Km/h
Answer:
I think it is B maybe A
Explanation:
NEED HELP ASAP question in picture
Answer:
B
Explanation:
I don't know how to break it down but I hope this is helpful!