Rahul and Sonia were playing with blocks and each of them made a train out of them. Both of them thought of measuring the length of the train using their handspan. By that time Rahul's friend Anupam came and suggested them to measure with a measuring tape for fair result. (a) They measured their train using their outstretched hand. What unit do you think they used? (b) Why Anupam asked both of them to use measuring tape? (c) What value of Anupam is shown here? (2.5M)
Answer:
They measured their train using their handspan
Let's say you want to start a fire using a mirror to focus sunlight. What would you do A) use a plane mirror. B) use a convex mirror , with the object to be ignited positioned at the center of curvature of the mirror. C) use a concave mirror, with the object to be ignited positioned at the center of curvature of the mirror. D) use a concave mirror, with the object to be ignited positioned halfway between the mirror and its center of curvature.
Answer:
A concave mirror is used.
Explanation:
start a fire using a mirror to focus sunlight.
A concave mirror is used as a light concentrator.
When the object is placed at the infinity, the image is formed at focus.
So, the light is focused at the focus and thus the fire is started.
PLSSSSS HELPPPPP
Consider the potential energy diagram shown below. This graph shows the chemical potential energy in a reaction system over time. The y-axis is potential energy in kilojoules. The x-axis is the reaction progress, or time.
The far left part of the curve is horizontal and has an energy value of 50 kJ. The curve then rises to a peak of 250 kJ before falling to a horizontal region at 200 kJ.
Does this graph represent an endothermic or an exothermic reaction? Explain your answer.
What is the enthalpy change, ΔH, for this reaction? Show your work.
What is the activation energy, Ea, for this reaction? Show your work.
In a particular chemical reaction, the energy of the reactants is 30 kJ and the energy of the products is 5 kJ. The maximum energy of the system is 40 kJ.
Sketch a potential energy diagram for this reaction. Make sure to label the energy of the reactants, the energy of the products, the activation energy, and the enthalpy change for the reaction.
What is the activation energy for this reaction?
What is the enthalpy change for this reaction?
Is this reaction endothermic or exothermic? Explain your answer in two ways: first, using the energy values, and second, by referring to the shape of the graph.
The coating on the head of a match is highly flammable. When it burns, it releases a great deal of energy. However, before the match can burn, it must gain a small amount of energy from a spark. That spark is typically produced by striking (rubbing) the match head against a rough surface. Sketch and describe a potential energy diagram that represents the striking and burning of the match. Remember to label the diagram with the energy changes that occur. Your answer must include the potential energy diagram and a written description. (Note: you do not have to use actual energy values.)
Answer:
A. Endothermic reaction.
B. +150KJ.
C. 250KJ.
Explanation:
A. The graph represents endothermic reaction because the heat of the product is higher than the heat of the reactant.
B. Determination of the enthalpy change, ΔH for the reaction. This can be obtained as follow:
Heat of reactant (Hr) = 50KJ
Heat of product (Hp) = 200KJ
Enthalphy change (ΔH) =..?
Enthalphy change = Heat of product – Heat of reactant.
ΔH = Hp – Hr
ΔH = 200 – 50
ΔH = +150KJ
Therefore, the enthalphy change for the reaction is +150KJ
C. The activation energy for the reaction is the energy at the peak of the diagram.
From the diagram, the activation energy is 250KJ.
If you have a cube that is 2x2x2 and weighs 5.29 g. How do you find the density?
Answer:
0.66
Explanation:
Follow the Density Formul d = m/v
so
d = 5.29/8
= 0.66 Density
Just correct me if I'm wrong, I mean like literally :> Thank you! ^^
describe the application of Pascal's law in hydraulic excavator.
plz help me
Explanation:
The hydraulic system works on the principle of Pascal's law which says that the pressure in an enclosed fluid is uniform in all the directions. ... As the pressure is same in all the direction, the smaller piston feels a smaller force and a large piston feels a large force.
Examine the following output:
4 22 ms 21 ms 22 ms sttlwa01gr02.bb.ispxy.com [154.11.10.62]
5 39 ms 39 ms 65 ms plalca01gr00.bb.ispxy.com [154.11.12.11]
6 39 ms 39 ms 39 ms Rwest.plalca01gr00.bb.ispxy.com [154.11.3.14]
7 40 ms 39 ms 46 ms svl-core-03.inet.ispxy.net [205.171.205.29] 8 75 ms 117 ms 63 ms dia-core-01.inet.ispxy.net [205.171.142.1] Which of these commands produced this output?
A. tracert
B. nslookup
C. pingroute
D. ping
Answer:
A. tracert
Explanation:
Tracert is a computer diagnostic command which displays possible routes for delays in packets of Internet Protocol (IP). Tracert command will display results for route which is recorded round trip times of packet.
Which type of reaction is modeled by this chemical equation?
2Li + CaCl2 → 2LiCl + Ca
O A. Single-replacement
O B. Combustion
O C. Synthesis
O D. Double-replacement
The correct answer is Option (A) Single replacement.
What is Single replacement Reaction?
The reaction substituted to the other element is called single replacement reaction.The general equation is A+BX-----> AX+B.Why other options are incorrect?(B) Combustion is a type of chemical reaction in which a compound and an oxidant is reacted to produce heat and a new product.
(C) Synthesis is the production of chemical compounds by reaction from simpler materials.
(D)A double replacement reaction is a type of chemical reaction where two reactants exchange ions to form two new products with the same type of chemical bonds.
Hence Other options are incorrect and (A) is the correct one
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Answer: single replacement
Explanation:
can someone please help
The answer is B. Mono and polyunsaturated fats because the other two are really harmful and they are not healthy whatsoever.
HELP)
of the following WOULD YOU NOT FIND IN THE DESERT
TORNADO
DRY HUMIDITY
HURRICANE
NONE OF THE ABOVE
the one you will most likely not find would be a hurricane
Explanation:
then can only be made when they are in a body of water
What produces magnetic fields?
Answer:
flowers
Explanation:
i'm really not sure but i have this gut feeling its flowers
A hydrometer is an instrument used to determine liquid density. A simple one is sketched in the figure below. The bulb of a syringe is squeezed and released to lift a sample of the liquid of interest into a tube containing a calibrated rod of known density. (Assume the rod is cylindrical.) The rod, of length L and average density 0, floats partially immersed in the liquid of density . A length h of the rod protrudes above the surface of the liquid. Show that the density of the liquid is given by
=
0L
L − h
.
(Do this on paper. Your instructor may ask you to turn in this work.)
Answer:
weight of rod =weight of liquid displaced
mass of the rod ×g =mass of liquid displaced ×g
(g cancelled out)
mass of the rod =mass of liquid displaced
density of rod ×volume of rod =density of liqiud ×volume of liquid displaced
O×cross section area of rod ×height of rod =density of liquid ×Cross section area of rod ×height of rod under the surface
O×L=density of liquid ×(L-h)
then density of liquid =OL/(L-h) shown as required
The density of the liquid is given by =OL/L − h
What is density?Density is the ratio of mass of an object and its volume.
According to the Archimedes principle, weight of rod = weight of liquid displaced
mass of the rod ×g =mass of liquid displaced ×g
So, mass of the rod =mass of liquid displaced
Mass in terms of density is substituted,
density of rod × volume of rod =density of liquid ×volume of liquid displaced
O× cross section area of rod ×height of rod =density of liquid ×Cross section area of rod ×height of rod under the surface
O×L=density of liquid ×(L-h)
Then, density of liquid =OL/(L-h).
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1. A 14-cm tall object is placed 26 cm from a converging lens that has a focal length of 13 cm.
Answer:
a) Please find attached the required drawing of light passing through the lens
By the use of similar triangles;
The image distance from the lens = 26 cm
The height of the image = 14 cm
c) The image distance from the lens = 26 cm
The height of the image = 14 cm
Explanation:
Question;
a) Determine the image distance and the height of the image
b) Calculate the image position and height
The given parameters are;
The height of the object, h = 14 cm
The distance of the object from the mirror, u = 26 cm
The focal length of the mirror, f = 13 cm
The location of the object = 2 × The focal length
Therefore, given that the center of curvature ≈ 2 × The focal length, we have;
The location of the object ≈ The center of curvature of the lens
The diagram of the object, lens and image created with MS Visio is attached
From the diagram, it can be observed, using similar triangles, that the image distance from the lens = The object distance from the lens = 26 m
The height of the image = The height of the object - 14 cm
b) The lens equation is used for finding the image distance from the lens as follows;
[tex]\dfrac{1}{u} + \dfrac{1}{v} = \dfrac{1}{f}[/tex]
Where;
v = The image distance from the lens
We get;
[tex]v = \dfrac{u \times f}{u - f}[/tex]
Therefore;
[tex]v = \dfrac{26 \times 13}{26 - 13} = \dfrac{26 \times 13}{13} = 26[/tex]
The distance of the image from the lens, v = 26 cm
The magnification, M =v/u
∴ M = 26/26 = 1, therefore, the object and the image are the same size
Therefore;
The height of the image = The height of the object = 14 cm.
define the term capacitance and its SI unit
Answer:
See explanation below
Explanation:
Capacitance is the amount of electric charge stored on a conductor and its SI unit is Farads (F).
Answer:
capacitance is the amount electric charges of a conductor, its si is farads
Bye , :-)
A cell supplies current of 0.6A and 0.2A through 1ohms and 4.0ohms resistor respectively. Calculate the internal resistance of the cell
0.5Ω
Explanation:Since different currents are passing through the resistors, then the resistors are most probably connected in parallel. This also means that the same voltage will pass across them.
Using Ohm's law, the voltage across a resistor in a circuit is given by;
V = I(R + r) -----------(i)
For the 1ohm resistor, the voltage across it is given by;
Where;
I = current passing through the 1 ohm resistor = 0.6A
R = resistance of the 1 ohm resistor = 1Ω
r = internal resistance of the cell = r
Substitute these values into equation (i) as follows;
V = 0.6(1 + r) -------------------(ii)
For the 4.0ohm resistor, the voltage across it is given by;
Where;
I = current passing through the 4.0 ohms resistor = 0.2A
R = resistance of the 4.0 ohms resistor = 4.0Ω
r = internal resistance of the cell = r
Substitute these values into equation (i) as follows;
V = 0.2(4.0 + r) -------------------(iii)
Now solve equations (ii) and (iii) simultaneously;
V = 0.6(1 + r)
V = 0.2(4.0 + r)
Substitute the value of V in equation (ii) into equation (iii). Therefore, we have;
0.6(1 + r) = 0.2(4.0 + r)
Solve for r
0.6 + 0.6r = 0.8 + 0.2r
0.6r - 0.2r = 0.8 - 0.6
0.4r = 0.2
r = [tex]\frac{0.2}{0.4}[/tex]
r = 0.5
Therefore, the internal resistance of the cell is 0.5Ω
why would the planets move in a straight path if there was no gravitational energy from the sun
Explanation:
The sun's gravitational force is very strong. If it were not, a planet would move in a straight line out into space. The sun's gravity pulls the planet toward the sun, which changes the straight line of direction into a curve. This keeps the planet moving in an orbit around the sun
Answer and Explanation:
The planets would move in a straight path since there would be no source that will be acting upon them (if the sun wasn't there).
Gravitational pull is the amount of force that an object emits. Due to the Sun having a larger mass and a larger gravitational pull, the planets orbit around it.
If, for example, a house was bigger than everything, including planets and stuff, those things would orbit around the house.
A real life example is the moon orbiting Earth. The Earth has a greater magnitude and mass, so it is able to pull the Moon.
Right now the Sun is the external force, as its gravitational pull is moving the planets around. IF the sun was to magically disappear, the planets won't follow an orbit anymore, since there isn't a gravitational pull on them. This leads them to going in a straight line for possibly a couple years.
Eventually, the planets will stop going in a straight line and start to orbit each other, leading to the planets eventually crashing.
External Force = Sun's gravitational pull because of bigger mass
The planets themselves were created after the sun (though some minerals were created before the sun, but that's minerals and not the planet entirely). The sun gives the planet's their motion. The planets, however (though I'm not sure about mercury and Venus) are going super fast, fast enough to where they aren't being pulled into the sun, but not fast enough to go out of orbit.
If the sun goes out magically, the planets, actually yes will continue orbit due to them being in that motion at such a fast rate, but eventually when they are supposed to turn again, (like, to another part of the sun), the would go straight. Eventually, the will get into the orbit of something else and start going around that object's orbit, most likely outcome being that they crash.
The excess force from no gravitational pull will make the planets go in a straight path. Since nothing is acting upon it, the planets would move in a straight line. Imagine if you were on those spinning circle things, and then let go. You would go around it for like a second and then go immediately straight in one direction.
#teamtrees #PAW (Plant And Water)
If you were to make a three-dimensional model of magnetic force using a magnet and magnetic field lines, which two characteristics might your model have
Answer:
- the Magnetic field lines will spread out of the north end of the magnet.
- the magnetic fields will three-dimensional and resemble a bubble.
Explanation:
- Usually, when drawing magnetic field lines, we start outwardly from the North pole to the South Pole. This same direction is also prevalent on the Earth due to the fact that the Earth functions as a giant magnet. Thus, one characteristic of the model is that the Magnetic field lines will spread out of the north end of the magnet.
- Another thing is that Magnetic field forces are usually driven as a result bubble like configuration which affects the objects that are in such a configuration. Thus, another characteristic of the model is that the magnetic fields will three-dimensional and resemble a bubble.
You hear the dishwasher with a loudness of 40 dB and a siren outside
with a loudness of 60 dB. How much greater is the amplitude of the
siren's sound than the amplitude of the dishwasher's sound?
Answer:
The ratio of the amplitudes of siren to dishwasher is 10.
Explanation:
loudness of dishwasher = 40 dB
loudness of siren = 60 dB
let the intensity of dishwasher is I an the intensity of siren is I'.
Use the formula of intensity and decibels.
[tex]dB = 10 log\frac{I}{I_o}\\\\40=10 log\frac{I}{I_o}\\\\4 = log\frac{I}{I_o}\\\\I = 10000 I_o[/tex]
And
[tex]60=10 log\frac{I'}{I_o}\\\\60 = log\frac{I'}{I_o}\\\\I' = 1000000 I_o[/tex]
The intensity if proportional to the amplitude.
[tex]\frac{A'}{A}=\sqrt\frac{1000000}{10000}\\\\\frac{A'}{A}= 10[/tex]
Dos carritos se colocan en una mesa sobre la que pueden moverse sin rozamiento y se sujetan comprimiendo un resorte entre ellos. El carrito 1 tiene doble masa que el 2. De pronto se sueltan. A) Compara las velocidades, cantidades de movimiento y energías cinéticas que adquieren, b) ¿Cómo serían las respuestas si la masa del carrito 1 fuese mucho mayor que la del 2?
Answer:
a) v₁ = - ½ v₂, K₁ / K ₂ = ½,)
Explanation:
A) Let's use the conservation of the moment, for this we define the system formed by the spring and the two cars, so the force during the separation is internal, therefore the moment is conserved
initial instant. Before releasing the carts
p₀ = 0
final instant. After jumping the cars
p_f = M v₁ + m v₂₂
how the moment was preserved
p₀ = p_f
0 = M v₁ + m v₂
v₁ = - m / M v₂
indicate that M = 2m
v₁ = - ½ v₂
the kinetic energy of each car is
K₁ = ½ M v₁²
K₁ = ½ 2m (v₂/ 2) ²
K₁ = m ₂v₂² / 4
K₂ = ½ m v₂²
the relationship between the kinetic energies is
K₁ / K₂ = ½
B) If the much greater than the mass of car 1 is mass of car 2
v = - m / M v₂
In this case, the speed of car 1 is very small, so the car 1 practitioner does not backtrack and car 2 leaves with a lot of speed.
The energy is still conserved, where almost all the energy has it is car 2
My buddy and I are planning a shore dive. we're descending onto a very gradual slope that begins at 5 m/15 ft, so our descent and ascent will be a gradual part of swimming out and back underwater. we have similar cylinders filled to 2000 bar/3000 psi. We plan:
- 50 bar/500 psi reserve
- 20 bar/300 psi for our safety stop
- to turn the dive when we've used 1/3 of the air available to use on the dive
This means we should head back when either of our SPGs read
A. 70 bar/800 psi
B. 145 bar/1900 psi
C. 157 bar/2270 psi
D. 170 bar/2500 psi
Answer:
C. 157 bar/2270 psi
Explanation:
Calculation to determine what we should head back when either of our SPGs read
SPGs=200 bar -[200 bar-(50 bar + 20 bar)]÷1/3]
SPGs=200 bar-[(200 bar-70 bar)÷1/3]
SPGs=200 bar-(130 bar÷1/3)
SPGs=200 bar-43 bar
SPGs=157 bar/2270 psi
Therefore based on the above calculation we should head back when either of our SPGs read 157 bar/2270 psi
How much current is drawn by a computer with a resistance of 42Ω that is connected across a potential difference of 220 V?
9200 amps
6.6 amps
7.0 amps
5.2 amps
Answer:
5.2 amps
Explanation:
V = I*R
I = V/R
I = 220/42
I = 5.2 amps
Answer:
5.2
Explanation:
because
[tex]i \frac{v}{r} [/tex]
220÷42=5.23
negative acceleration is also known as
Answer:
Deceleration
Explanation:
The amount by which a speed or velocity decreases
Answer:
Negative Acceleration is called Deceleration.
100 J OF HEAT IS PRODUCED EACH SECOND IN A 4 COULUMB RESISTER. THE POTENTIAL DIFFERANCE ACROSS THE RESISTER WILL BE
Answer:
The correct answer is "20 Volts".
Explanation:
Given:
Heat,
H = 100 J
Resistance,
R = 4 Ω
As we know,
⇒ [tex]P=\frac{v^2}{R}[/tex]
By putting the values, we get
⇒ [tex]100=\frac{v^2}{4}[/tex]
⇒ [tex]v^2=100\times 4[/tex]
⇒ [tex]=400[/tex]
⇒ [tex]v=\sqrt{400}[/tex]
⇒ [tex]=20 \ volts[/tex]
Pls help it’s really late <3
Answer:
22.4%
Explanation:
The plane is 300000 kg
It is 11000 meters about the earth's surface.
g = 9.81
PE = mgh
PE = 300000 * 9.81 * 11000
PE = 3.24* 10^10
The Kinetic Energy
KE = 1/2 m * v^2
m = 300000
v = 250 m/s
KE = 1/2 300000 * (250 m/s)^2
KE = 9.375 * 10^9
Total Energy = 3.24 * 10^10 + 9.375 * 10^9
Total Energy = 4.17 * 10^10
9.375 * 10^9
=========== * 100 % = 22.44 %
4.17 * 10^10
which instrument should, ideally, have zero resistance?
A) wheatstone bridge
B) oscilloscope
C) voltmeter
D) ammeter
300kg of water are lifted 10m vertically in 5s show the work done in 30kj and that power is 6kw . Please help me
Answer:
6KW
Explanation:
The computation is shown below:
We know that
Work done= m ×g× h
Here
W= 300×10×10
= 30000 J
= 30 KJ
And
Power= Work done ÷time taken
P = 30000 ÷ 5
= 6000W
= 6KW
The above represent the answer
Uas partículas com cargas = +1,0 e = +2,0 estão posicionadas conforme indica a figura. Determine o módulo do campo eléctrico resultante no ponto P, em N/C.
Which statement about the mass and the weight of an object is correct?
A They are both affected by changes in the acceleration of free fall.
B They are both forces.
C They have different units.
D Weight is calculated by dividing mass by the acceleration of free fall.
Answer:
HOPE IT HEPLED U !!!!
Explanation:
i think it's (C) They have different units ....
A car with a velocity of 22 m/s is accelerated uniformly at the rate of 2 m/s2 for 7s. What is its final velocity?
Answer:
Explanation:
This is a classic acceleration problem in one dimension. Use the equation
[tex]a=\frac{v_f-v_0}{t}[/tex] where a is the acceleration of he car, vf is the final velocity (and our unknown), v0 is the initial velocity, and t is time in seconds. Filling in:
[tex]2=\frac{v_f-22}{7}[/tex] and
14 = vf - 22 and
36 = vf (not quite right with the sig dig's but I'm guessing you're not really into the specifics much, judging by the acceleration and the time values)
A child has a mass of 30 kg on Earth. If th gravity on Moon is one sixth that of the Earth what is the weight of the child on the Moon? Gravity on Earth = 10 N^-1
Answer:
the baby would still be 30 kg on the moon because that’s mass, not weight.
However, it will feel like 5 kg, because the acceleration is 1/6 and the force is 1/6 and the actual weight (product of mass and acceleration will be 1/6).
The child has a mass of 30 kg on earth and has one-sixth gravity on the moon will have a weight of 50 kg on the moon.
What is Gravity?Gravity is a fundamental interaction that causes all objects with mass or energy to attract one another. The weakest of the four fundamental interactions is gravity, by far. The Moon's gravity causes sublunar tides in the oceans, just as gravity on Earth imparts weight to physical objects.
Given:
The mass of the child (m) = 30 kg,
The gravity on the moon (G) = 1/6 of the earth.
To calculate the weight of the child on the moon, use the formula given below,
F = m × a
Here
[tex]F[/tex] is the weight, [tex]m[/tex] is the mass and [tex]a[/tex] is the gravity on earth, gravity on earth [tex]10\ m/s^2[/tex].
Substitute the values
[tex]F=30*10/6[/tex]
[tex]F = 50\ kg[/tex]
Therefore, the weight of a child on the moon is 50 kg.
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A 40kg girl and a 50kg boy are facing each other on a friction-free rollerskates. The girl pushes the boy, who moves away at a speed of 3 m/s. What is the girl's
speed?
Your answer
Answer:
Explanation:
The Law of Momentum Conservation, just like the Law of Thermodynamics about energy, says that momentum is neither created nor destroyed but is conserved, meaning it has to go somewhere. If the girl pushes the boy and they are both on friction free skates, then the girl will also react to the push. Momentum Conservation says
[tex](m_gv_g+m_bv_b)_b=(m_gv_g+m_bv_b)_a[/tex] In words this says that the mass times the velocity of the girl plus the mass times the velocity of the boy before the push has to equal the mass times velocity of the girl plus the mass times velocity of the boy after the push. Mathematically,
[tex](40.0*0+50.0*0)_b=(40.0v+50.0*-3)_a[/tex]
The left side of this is equal to 0. On the right, I made the velocity of the boy negative. We could have made it positive and it wouldn't have mattered. The sign will only be important to the result because if the sign of the girl's velocity is the same as the boy's, she is moving in the same direction as he is; if it's different, she is moving in the opposite direction.
0 = 40.0v - 150.0 and
-40.0v = -150.0 so
v = 3.75 This means that when she pushes the boy one way, mometum is conserved and she moves in the opposite direction and at a greater velocity (because her mass is less). Physics is a wonderful thing, isn't it!?