Answer:
1306.67 s
Explanation:
From the question given above, the following data were obtained:
Volume of water = 70 L
Power (W) = 18000 w
Specific heat capacity (C) = 4200 J/g℃
Initial temperature (T1) = 20 ℃
Final temperature (T2) = 100 ℃
Time (t) =?
Next, we shall determine the mass of the water. This can be obtained by converting 70 L to kg. This is illustrated below:
1 L = 1 kg
Therefore,
70 L = 70 Kg
Thus, the mass of the water is 70 kg.
Next, we shall determine the heat energy involved. This is can be obtained as follow:
Mass (M) of water = 70 Kg
Specific heat capacity (C) = 4200 J/g℃
Initial temperature (T1) = 20 ℃
Final temperature (T2) = 100 ℃
Heat Energy (Q) =?
Q = MC(T2 – T1)
Q = 70 × 4200 × (100 – 20)
Q = 294000 × 80
Q = 3520000 J
Thus, the heat energy involved is 3520000 J
Finally, we shall determine the time taken.
Power (W) = 18000 w
Heat Energy (Q) = 3520000 J
Time (t) =?
Power = energy / time
18000 = 3520000 / time
Cross multiply
18000 × time = 3520000
Divide both side by 18000
Time = 3520000 / 18000
Time = 1306.67 s
The number of student of schoolwas 450 last year and it is 396 this year.By how many percent did the number decrease
Answer:
12%
Explanation:
number of students decreased=54
percentage of students decreased= 54/450 x 100
=12%
A student designs an experiment to demonstrate the conservation of gravitational potential and kinetic energy. She drops a wooden block from rest through a photogate 2 m below. If energy is conserved, how fast should the block be traveling when it passes through the photogate?
A.
2.0 m/s
B.
6.3 m/s
C.
9.8 m/s
D.
19.6 m/s
Answer:
6.3 m/s
Explanation:
A student drops a wooden block from rest through a photogate 2 m below. Since there is a conservation of the gravitational potential energy and the kinetic energy, the final speed of the block is B. 6.3 m/s.
Gravitational potential energy and kinetic energyGravitational potential energy: is the potential energy a massive object has in relation to another massive object due to gravity.Kinetic energy: is a form of energy that an object or a particle has by reason of its motion.A wooden block is dropped from rest. If energy is conserved, the initial gravitational potential energy (U₁) will be equal to the final kinetic energy (K₂).
U₁ = K₂
m × g × h₁ = 1/2 × m × v₂²
where,
m is the mass of the object.g is the gravity.h₁ is the initial height.v₂ is the final speed.m × g × h₁ = 1/2 × m × v₂²
g × h₁ = 1/2 × v₂²
v₂ = √(2 × g × h₁)
v₂ = √(2 × (9.8 m/s²) × 2 m) = 6.3 m/s
A student drops a wooden block from rest through a photogate 2 m below. Since there is a conservation of the gravitational potential energy and the kinetic energy, the final speed of the block is B. 6.3 m/s.
Learn more about conservation of energy here: https://brainly.com/question/14525402
Please help me with this.
Question 7 of 10 What causes magnetic domains? O A. Magnetic poles of magnets attracting each other O B. Electricity moving through iron O C. Magnetic fields of atoms aligning D. Iron being placed near a magnet.
Answer:
C. Magnetic fields of atoms aligning
Answer:
c
Explanation:
a pex
Two balls, ball A and ball B, are dropped from the same height onto the same surface. If ball A rebounds to a higher height than ball B then:(3) A. ball A is more elastic than ball B. B. ball B is more elastic than ball A. C. not enough information is given to determine which ball is more elastic.
Answer:
its b
Explanation:
Patriotism and education are traditional American values. Please select the best answer from the choices provided T F
Answer:
True
Explanation:
It is a true statement that "Patriotism and education are traditional American values."
The United States of AmericaThe United States of America are bound together by certain core values that hold the entire country together. These values are reverberated any time the ideals of the country are discussed.
Two of the key values of the American society are;
PatriotismEducationHence, it is a true statement that "Patriotism and education are traditional American values."
Learn more about patriotism: https://brainly.com/question/779632
Difference between rest and motion?
Answer:
Rest and motion are relative terms. In simple terms, an object that changes its position is said to be in motion while the opposite action causes an object to be at rest.
Explanation:
an ice Puck travels 18 m in 3 S before it slides into the goal what is the speed of the traveling puck
Answer:
[tex]\boxed {\boxed {\sf 6 \ meters \ per \ second}}[/tex]
Explanation:
Speed can be found by dividing the distance by the time.
[tex]s=\frac{d}{t}[/tex]
The distance is 18 meters and the time is 3 seconds.
[tex]d= 18 \ m \\t= 3 \ s\\[/tex]
Substitute the values into the formula.
[tex]s=\frac{18 \ m }{ 3 \ s }[/tex]
Divide.
[tex]s= 6 \ m/s[/tex]
The speed of the puck is 6 meters per second.
Answer:
Given :-Distance travelled (D) = 18 mTime taken (T) = 3 secondTo Find :-Speed
Solution :-As we know that
[tex] \sf Speed = \dfrac{Distance}{Time} [/tex]
[tex] \sf \: Speed = \dfrac{18}{3} [/tex]
Cancelling both by 3
[tex] \sf \: Speed = 6 \: mps[/tex]
Robin throws a penny up in the air. If the penny's initial velocity is 1.0m/s[up] and it is launched from a height of 1.5 m, what is the maximum height of the penny above the ground?
Answer:
1.55m
Explanation:
The formula for calculating the maximum height is expressed as;
H = u²/2g
u is the initial velocity
g is the acceleration due to gravity
Substitute
H = 1²/2(9.8)
H = 1/19.6
H = 0.051m
Since it is launched form a height of 1.5m, the height above the ground will be 1.5+0.051 = 1.55m
who was the first president of the united states
Answer:
George Washington
Explanation:
Answer:
well for me
Explanation:
It was George Washington
a stone is tied to one end of string. holding to the other end , the string is whirled in the horizontal plane with progressively increasng speed it breaks at some speed bexause
Answer:
Breaks because it doesn't have force in the radial direction and thus due to inertia the stones will fly off tangentially.
Explanation:
Until the stone is tied to a string, it will possess centripetal force and centrifugal force along the radial direction of motion due to the tension present in the string. Now, when the rope breaks, it breaks because it doesn't have force in the radial direction and thus due to inertia the stones will fly off tangentially.
A 4000-kg car bumps into a stationary 6000kg truck. The Velocity of the car before the collision was +4m/s and -1m/s after the collision. What is the velocity of the truck?
Answer:
The velocity of the truck is 3.33 m/s
Explanation:
Law Of Conservation Of Linear Momentum
The total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and velocity v is
P=mv.
If we have a system of bodies, then the total momentum is the sum of the individual momentums:
[tex]P=m_1v_1+m_2v_2+...+m_nv_n[/tex]
If some collision occurs, the velocities change to v' and the final momentum is:
[tex]P'=m_1v'_1+m_2v'_2+...+m_nv'_n[/tex]
In a system of two masses:
[tex]m_1v_1+m_2v_2=m_1v'_1+m_2v'_2[/tex]
There are two objects: The m1=4000 Kg car and the m2=6000 Kg truck. The car was moving initially at v1=4 m/s and the truck was at rest v2=0. After the collision, the car moves at v1'=-1 m/s. We need to find the velocity of the truck v2'. Solving for v2':
[tex]\displaystyle v'_2=\frac{m_1v_1+m_2v_2-m_1v'_1}{m_2}[/tex]
Substituting:
[tex]\displaystyle v'_2=\frac{4000*4+6000*0-4000(-1)}{6000}[/tex]
[tex]\displaystyle v'_2=\frac{16000+4000}{6000}[/tex]
[tex]\displaystyle v'_2=3.33[/tex]
The velocity of the truck is 3.33 m/s
What would most likely cause the future acceleration of the expansion of the universe
Radiation
The existence of background radiation
Light shifts identified by Doppler effect
Answer:
never scared
that might help you
Imagine that it is summer solstice in the Northern Hemisphere. What is the date, and where is the Sun? What is happening in the Southern Hemisphere? Please help
21 june is the date......hopi it will help
Answer:
June 22 North Pole tited to the sun, and its winter in the southern hemesphere
Explanation:
If a small motor does 520 J of work to move a toy car 260 m in 3.0 seconds, how much power is being applied by the motor?
Answer:
P = 173.33 [W]
Explanation:
Power is defined as the amount of work done over a given time.
W = work = 520 [J]
t = time = 3 [s]
P = power [w]
Therefore by working relationship over time we can calculate the power.
[tex]P =W/t\\P = 520/3\\P=173.33[W][/tex]
1. What is the velocity of a go-kart with a mass
of 25 kg and 50 J of kinetic energy?
Answer:
Explanation:
The formula for KE is
[tex]KE=\frac{1}{2}mv^2[/tex] which makes solving our problem for velocity super easy. We will rewrite the formula in terms of v to get:
[tex]v=\sqrt{\frac{2KE}{m} }[/tex] and filling in:
[tex]v=\sqrt{\frac{2(50)}{25} }[/tex] so
v = 2 m/s to the correct number of sig fig's
PLZ HELP I DON'T UNDERSTAND!! a boy is playing catch with his friend. He throws the ball straight up. When it leaves his hand, the ball (2kg) is traveling 10m/s. Whats the ball's kinetic energy just as it leaves the boy's hand? What is the potential energy of the ball when it reaches the highest point?
Explanation:
The mass of a ball, m = 2 kg
It is traveling with a speed of 10 m/s
The ball's kinetic energy just as it leaves the boy's hand is calculated as follows :
[tex]K=\dfrac{1}{2}mv^2\\\\K=\dfrac{1}{2}\times 2\times (10)^2\\\\=100\ J[/tex]
The ball's kinetic energy just as it leaves the boy's hand is 100 J. The potential energy of the ball when it reaches the highest point is same as the kinetic energy as it leaves the boy's hand.
Hence, the required kinetic and potential energy is 100 J.
A tourist stands at the top of the Grand Canyon, holding a rock, overlooking the valley
below. Find the final velocity, and displacement of the rock after 4.0 seconds give the three
initial conditions listed below.
Answer:
a. Vf = 39.24 [m/s]
b. Vf = 31.24 [m/s]
c. Vf = 47.24 [m/s]
Explanation:
To solve this problem we can use the following equation of kinematics. We have to keep in mind that the gravitational acceleration acts downwards, therefore when the rock falls towards the abyss it has the same direction of the acceleration and that is why the gravitational acceleration has a positive sign in the equation.
[tex]v_{f}=v_{o}+g*t[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (when the rock is dropped)
g = gravitational acceleration = 9.81 [m/s²]
t = time = 4 [s]
a.
[tex]v_{f}=0+9.81*4\\v_{f}= 39.24 [m/s][/tex]
b.
In this particular situation, the acceleration will be taken as negative because the gravity is pointing in the opposite direction of the movement of the rock.
[tex]v_{f}=8-(9.81*4)\\v_{f}=-31.24[m/s][/tex]
The negative sign in the answer tells us that the rock no longer moves up instead it does downwards when 4 seconds have passed.
c.
[tex]v_{f}=8+(9.81*4)\\v_{f}=47.24[m/s][/tex]
A 150-turn coil of wire moves perpendicularly through a uniform magnetic field in 1.1 s. If the field increases uniformly from 0.00 T to 0.95 T and each coil of wire has an area of 1.4 m2, use Faraday’s law of magnetic induction to find the magnitude of the induced emf in the coil:
a. 180 V
b. 1800 V
c. -180 V
d. -18 V
Answer:
-180 V
Explanation:
Given that,
No. of turns, N = 150
If the field increases uniformly from 0.00 T to 0.95 T and each coil of wire has an area of 1.4 m²
The coil will move perpendicular through a uniform magnetic field in 1.1 s.
We need to find the magnitude of the induced emf in the coil. The formula for the induced emf is given by :
[tex]\epsilon=\dfrac{-d\phi}{dt}\\\\=\dfrac{-d(BA)}{dt}\\\\=-A\dfrac{dB}{dt}[/tex]
Put all the values,
[tex]\epsilon=-NA\dfrac{dB}{dt}\\\\=-150\times 1.4\times \dfrac{0.95-0}{1.1}\\\\=-181.36\ V[/tex]
Out of four options, induced emf is (-180 V)
So, induced emf in the coil is (-180 V). Hence, the correct option is (c).
Hope this helps.......☺
Electricity costs 10p per unit. How much will it cost Sam to use a 85W laptop and a 60W lamp for an hour?
It will cost Sam "1.45 p. per hr" to use an 85W laptop and a 60W lamp. To understand the calculation, check below.
Power and ElectricityAccording to the question,
Electricity cost = 10 p per unit
Laptop power = 85 W
Lamp power = 60 W
We know the standard unit, KW/hr = 1000 W/hr
then,
= 85 + 60
= 145 W
By fractioning,
= [tex]\frac{145}{1000}[/tex]
= 0.145 KWH
hence,
The cost will be:
= 0.145 × 10 p
= 1.45 p. per hr
Thus the above approach is correct.
Find out more information about electricity here:
https://brainly.com/question/11517288
what is meant by lenght
Answer:
the size of something from one end to the other; how long something is
A little girl jumps up from the ground. What force makes her move up?
Answer:
Gravity (please mark me as the brainiest)
Explanation:
Gravity is a force caused by a large body, such as the Earth. Gravity pulls objects toward the Earth.
And give me a thanks, or vote
Two bodies of mass 10 kg each are separated by 1 metre, the force of attraction between them is
a) 6.67 x 10-N b) 6.67 x 10'N c) 6.67 x 10 N d) 6.67 x 10'Nial
99
Answer:
6.67x10^-11 N-m^2/kg^2
Explanation:
What is the mass of 2.5 moles of carbon?
A-1.5 x 1024 g C
B-30 g C
C-2.5 g C
D-0.21 g C
Answer:
I think no B
if wrong correct me plsssssss
Mark me brainliest
have a nice day
I will always help you understanding your assingments
#Captainpower:)
Use the diagram below to answer for the following questions for 2 points each:
1. Explain the difference between kinetic and potential energy.
2. Select two points where potential energy is seen and compare the amount of energy at each point.
2. Select two points where kinetic energy is seen and compare the amount of energy at each point.
Answer:
1. kinetic is when an object is moving and potential where the object is place
2. W and Y
3. X and Z
Enter the appropriate word(s) to complete the statement. (Choose from the words between parentheses)
In a inelastic , elastic)-
collision, both momentum and kinetic energy are conserved
-
Answer:
The correct option is;
Elastic
Explanation:
In an elastic collision, the initial kinetic energy of the system is equal to the final kinetic energy of the system, such that there is no loss in the net kinetic energy available at a specific time or stage in the system
Therefore, we have;
1/2·m₁·v₁₁² + 1/2·m₂·v₂₁² = 1/2·m₂·v₁₂² + 1/2·m₂·v₂₂²
From which we get;
m₁·v₁₁ + m₂·v₂₁ = m₂·v₁₂ + m₂·v₂₂
Which is indicates that the initial and momentum of the system is also conserved
Therefore, in an elastic collision, both momentum and kinetic energy are conserved.
Jupiter has the strongest gravity of any planet in our solar system. Which quantity will be a maximum there?
A. Density
B. Weight
C. Volume
D. Mass
Answer:
I think the answer is D
Explanation:
I dont have an explanation
Neeeee rnnnn ASAP offering 55 points CER: Brielle pushes a shopping cart through the store with an acceleration of 2
m/s2. The mass of the shopping cart with the groceries in it is 22 kg. Guiding
Question: How can Brielle increase the acceleration of the shopping cart?
Answer:
Decease the mass
Increase the force applied
Explanation:
To increase the acceleration of the shopping cart, Brielle should reduce the load inside her cart.
According to Newton's second law of motion;
Force = mass x acceleration
Now, mass is indirectly proportional to the acceleration. The more the mass, the lower the acceleration a body will generate.
Lighter bodies moves with a faster acceleration.
In this case the force applied is constant.
If the force applied is also, increased the acceleration of the body will increase also.
Is folding aluminum foil a chemical or physical change?
Answer:
Aluminum foil is a physical change. A further explanation is given below.
Explanation:
The processing of aluminum foil starts with either a succession of cool rolling procedures, wherever another density including its aluminum alloy becomes diminished by half amongst every method. Aluminum foil modified thickness and weight, but it would be an aluminum sheet, so it would be a physical transition or change.is anti-nodes and amplitude same
Explanation:
Antinodes are not the same thing as the amplitude , but they are very closely related. The amplitude is the distance from the rest position of the wave to the antinode . The antinode is just a point along the wave that has the greatest maximum velocity in the y-direction.
The amplitude of a standing wave doesn't remain the same throughout the wave. It keeps on changing as it is a function of x.
Where the amplitude is minimum is called?
The locations at which the absolute value of the amplitude is minimum are called nodes, and the locations where the absolute value of the amplitude is maximum are called antinodes.
Explanation:
Antinodes are not the same thing as the amplitude , but they are very closely related. The amplitude is the distance from the rest position of the wave to the antinode . The antinode is just a point along the wave that has the greatest maximum velocity in the y-direction .
intro urself please
what is the correct answer?
Answer:
in my calculation the answer is letter a but in goo gle the answer is letter c
which one will you trust?
Explanation:
dont report me or i will report you