Answer:
its two valence electrons
Explanation:
Calcium is a group 2 element with two valence electrons. Therefore, it is very reactive and gives up electrons in chemical reactions.
UR WELCOME!! :)
What produces magnetic fields?
Answer:
flowers
Explanation:
i'm really not sure but i have this gut feeling its flowers
A ball hits a wall. What is true about the magnitude of the force experienced by the ball compared with the force experienced by the wall?
A. The ball experiences more force than the wall.
B. The ball experiences less force than the wall.
The ball and the wall experience the same force.
D. The ball experiences half the force of the wall.
Reset
Next
Answer:
The ball and the wall experience the same force.
Explanation:
According to the third law of Newton, which states that "for every action, there is an equal and opposite reaction", this means that when an object 1 acts on object 2 with a certain force, object 2 also acts on object 1 with the same magnitude of force but in an opposite direction.
According to this question, a ball hits a wall with a certain force. This means that the wall will react on the ball with the same force magnitude, but in an opposite manner. Hence, the ball and the wall experience the same force.
If youre walking from point a to b, the magnitude of your displacement will always be equal or less than or greater than your distance?
The magnitude of your displacement can be equal to the distance you covered, or it can be less than the distance you covered. But it can never be greater than the distance you covered.
This is because displacement is a straight line, whereas distance can be a straight line, a squiggly line, a zig-zag line, a line with loops in it, a line with a bunch of back-and-forths in it, or any other kind of line.
The straight line is always the shortest path between two points.
A bungee cord has a spring constant of 82.5 N/m. After jumping, a person oscillates with a period of 7.50 s. What is the mass of the person?
Answer:
Explanation:
T = 2π √ (m/k)
T / 2π = √ (m/k)
T√k = 2π √m
(T√k) / 2π = √m
( (T√k) / 2π)^2 = m
m = ( (7.5√82.5) / 2π)^2
m = 117.66 Kg
Thermal physics vs atomic physics ...which is easier?
Answer:
Thermal physics
Explanation:
Because it uses temperature
Answer:
In my opinion both are easier if you'll work hard on it...
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
Which of the following is an elastic collision?
A.
A wad of gum sticking to a window
B.
Two cars colliding and sticking together
C.
A vase falling to the floor and shattering
D.
A tennis racquet hitting a ball
Answer: D
Explanation:
An elastic collision is a collision in which there is no net loss in kinetic energy in the system as a result of the collision. Both momentum and kinetic energy are conserved quantities in elastic collisions. Suppose two similar trolleys are traveling toward each other with equal speed.
A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75.0 cm . The power is off for 40.0 s , and during this time the flywheel slows down uniformly due to friction in its axle bearings. During the time the power is off, the flywheel makes 210 complete revolutionsAt what rate is the flywheel spinning when the power comes back on(in rpm)
Complete Question
A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75.0 cm . The power is off for 40.0 s , and during this time the flywheel slows down uniformly due to friction in its axle bearings. During the time the power is off, the flywheel makes 210 complete revolutions. At what rate is the flywheel spinning when the power comes back on(in rpm)? How long after the beginning of the power failure would it have taken the flywheel to stop if the power had not come back on, and how many revolutions would the wheel have made during this time?
Answer:
[tex]\theta=274rev[/tex]
Explanation:
From the question we are told that:
Angular velocity [tex]\omega=510rpm[/tex]
Mass [tex]m=40.kg[/tex]
Diameter d [tex]75=>0.75m[/tex]
Off Time [tex]t=40.0s[/tex]
Oscillation at Power off [tex]N=210[/tex]
Generally the equation for Angular displacement is mathematically given by
[tex]\theta_{\infty}=\frac{w+w_0}{t}t[/tex]
[tex]w=\frac{2*\theta_{\infty}}{t}-w_0[/tex]
[tex]w=\frac{28210}{40*(\frac{1}{60})}-510[/tex]
[tex]w=120rpm[/tex]
Generally the equation for Time to come to rest is mathematically given by
[tex]t=(\frac{\omega_0}{\omega_0-\omega})t[/tex]
[tex]t=(\frac{510}{510-120rpm})(40.0)(\frac{1}{60})[/tex]
[tex]t=0.87min[/tex]
Therefore Angular displacement is
[tex]\theta =(\frac{120+510}{2})0.87[/tex]
[tex]\theta=274rev[/tex]
Calculate the capacitance of a system that stores 9.4 x 10-10 C of charge at
Q
50.0 V. Use C=
AV
O A. 1.9 x 10-11 F
OB. 4.7 x 10-8 F
O C. 5.3 x 1010 F
O D. 2.1 x 107 F
Answer:
A. [tex]1.88\times 10^{-11}\,F[/tex].
Explanation:
By definition of Electric Capacitance, the capacitance of the system ([tex]C[/tex]), in farads, is described by the following formula:
[tex]C = \frac{q}{V}[/tex] (1)
Where:
[tex]q[/tex] - Electric charge, in coulombs.
[tex]V[/tex] - Voltage, in volts.
If we know that [tex]q = 9.4\times 10^{-10}\,C[/tex] and [tex]V = 50\,V[/tex], then the capacitance of the system is:
[tex]C = \frac{9.4\times 10^{-10}\,C}{50\,V}[/tex]
[tex]C = 1.88\times 10^{-11}\,F[/tex]
The correct answer is A.
Why is using the same cutting and knife for both
cooked and uncooked food not a drisable?
Answer:
It spreads diseases.
Explanation:
But when cooked food is kept on the place where uncooked meat or food was kept the germs spread to the cooked food also and as the cooked food cannot be washed it harms us as we directly consume it.
Calcalculate potential energy given to a potato sack having a mass of 2 kg as I raise it to a height of 450 CM
Answer:
8.829 Joules
Explanation:
The potential energy of an object, is the energy it posses (the energy stored within the object) by virtue of its relative elevation or height, position, state, or arrangement
The potential energy of an object raised to a given height, P.E. = m·g·h
Where;
m = The mass of the object
g = The acceleration due to gravity, a constant ≈ 9.81 m/s²
h = The present height of the object
For the potato sack having a mass, m = 2 kg, and raised to a height, h = 450 cm = 0.45 m, we have;
The potential energy given to the potato sack, by raising its height, P.E. is given as follows;
P.E. = 2 kg × 9.81 m/s² × 0.45 m = 8.829 Joules
The potential energy given to the potato sack, P.E. = 8.829 Joules
Date:
Page:
# Excercise.
7.
A very short answer questions.
what is acceleration due to gravity? what is
value of 'g’ on equatorial region and
polar region of the earth?
the
Answer:
See the answer below
Explanation:
Acceleration due to gravity (g) is the accelerational force experienced by a body as a result of the influence of the earth's gravitational force. It is a vector quantity, that is, it has both magnitude and direction.
The acceleration due to gravity is inversely proportional to the square of the radius of the earth. Hence, g at the equatorial region is slightly lesser (9.780 m/s2) than that of the polar regions (9.832 m/s2) of the earth because the earth bulges at the equator leading to a higher radius than at the poles.
An ohmic dipole of resistance 100 ohm is crossed by a current of intensity 120 ma. Calculates the voltage across this chemical dipole
Answer:
12.0 Volt
Explanation:
Step 1: Given data
Resistance of the ohmic dipole (R): 100 Ohm
Intensity of current (I): 120 mA (0.120 A)
Step 2: Calculate the voltage (V) across this chemical dipole
To calculate the voltage across the ohmic dipole, we will use Ohm's law.
I = V/R
V = I × R
V = 0.120 A × 100 Ohm = 12.0 V
As a train starts from rest then accelerates down the track, coming toward an observer faster and faster, the frequency of the sound waves coming toward the observer will be
Answer:
Increase in frequency constantly
Explanation:
This concept can be explained by Doppler shift as per which any form of disturbance spreads out spherically from its point of origin. If the source of sound wave is stationary and the receiver is also stationary, then the frequency remains the same but if the source is moving, then the disturbance caused is closer on one side and distant on the other side thereby producing shorter wavelength in direction the source is moving and longer wavelength in the opposite direction.
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.
How much gravitational potential energy does an object have if it is located 20 m above the point that we define as O height and has a mass of 10 kg
Answer:
Explanation:
PE = mgh where m is the mass in kg, g is the pull of gravity which is 9.8, and h is the height of the object above the point to which it could possibly fall, measured in meters. Plugging in:
PE = 10(9.8)(20) so
PE = 1960 J
This should be rounded to 1 sig fig according to the rules of sig fig and your numbers here, but I imagine you're not following them all that much. It should be 2000 J
name 4 element of weather
Answer:
They are temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness. Together, these components describe the weather at any given time.
Choose the incorrect statement about the proton: Group of answer choices The proton has the atomic mass of 1 amu The proton has the same charge as the neutron. The proton has greater mass than an electron The proton and the neutron have approximately the same atomic mass
Answer:
The proton has the same charge as the neutron.
Explanation:
Because the proton has a positive charge whereas the neutron has no charge at all.
A student is building an electric circuit.Which material should she choose for the wires,and why?
If i understand your question clearly, The best choice in most scenarios is copper.
Why?
Its due to copper's high conductive properties, its abundance, its low price compared to its fellow metal conductors, its ductile property, thermal resistance and immunity to oxidation ( rusting ).
Though Silver surpasses copper in conductivity, copper is shown to be more notable than its fellow conductors.
How sun directly overhead effects climate?
Answer:
The amount of heat energy received at any location on the globe is a direct effect of Sun angle on climate, as the angle at which sunlight strikes Earth varies by location, time of day, and season due to Earth's orbit around the Sun and Earth's rotation around its tilted axis.
Answer:
The earth's climate system depends entirely on the sun for its energy. Solar radiation warms the atmosphere and is fundamental to atmospheric composition.
Explanation:
hope this helps :)
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.
31) A box is pushed, up a ramp, at constant velocity with a force of 14 N.
What is the magnitude of the friction force working on the box? *
The magnitude of the frictional force working on the box is 14 N.
According to Newtons's first law, an object will continue in its state of rest or state of uniform motion unless it is acted upon by an unbalanced force. This means that motion or acceleration is caused by an unbalanced force.
Since the box is moving at constant velocity, the frictional force on the box and the force that moves the box forward are exactly equal in magnitude but opposite in direction.
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What is the amount of change in an object's momentum equal to?
A.
The amount of mass applied to the object over a certain amount of time
B.
The amount of force applied to the object over a certain amount of time
C.
The amount of acceleration applied to the object over a certain amount of time
D.
The amount of energy applied to the object over a certain amount of time
answer:
Explanation:
the impulse-momentum theorem states that the change in momentum of an object equals the impulse applied to it. The impulse-momentum theorem is logically equivalent to Newton's second law of motion (the force law).
According to the impulse-momentum theorem, the amount of change in an object's momentum equal to the amount of force applied to the object over a certain amount of time. So, option B.
According to the impulse-momentum theorem, the impulse that is applied to an item is equal to the change in momentum.
It shows how an object's change in momentum depends on both the strength and duration of the applied forces.
Impulse is defined as the force acting for a short interval of time.
Impulse = F x t
The momentum of the object,
P = mv
So, the rate of change of momentum,
dP/dt = d(mv)/dt
dP/dt = mdv/t
dP/dt = ma = Force
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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]
A motorcycle daredevil plans to ride up a 2.0-m-high, 20∘ ramp, sail across a 10-m-wide pool filled with hungry crocodiles, and land at ground level on the other side. He has done this stunt many times and approaches it with confidence. Unfortunately, the motorcycle engine dies just as he starts up the ramp. He is going 10.4 m/s at that instant, and the rolling friction of his rubber tires (coefficient 0.02) is not negligible. Part A: Justify your answer by calculating the distance he travels through the air after leaving the end of the ramp.
Answer:
The motorcycle daredevil does not sail across the 10-m wide pool filled with hungry crocodiles
Explanation:
The given parameters are;
The height of the ramp = 2.0 m-high
The angle of elevation of the ramp, θ = 20°
The width of the pool = 10 m
The speed with which he is going when the engine fails = 10.4 m/s
The rolling friction between the rubber tires, μ = 0.02
μ·g·cos(θ) = (1/2)·(a)
a = (μ·g·cos(θ))/(1/2)
Where;
a = The acceleration down the plane
∴ a = 0.02 × 9.81 × cos(20°)/(1/2) ≈ 0.369
The length of the ramp, l = 2.0 m/(sin(20°)) ≈ 5.8476088 m
The velocity at the end of the ramp, v² = u² - 2·a·l
∴ v² = 10.4² - 2×(0.369 + 9.81 × sin(20°))×5.8476088 ≈ 64.60446471
v ≈ √(64.60446471) ≈ 8.04
∴ The velocity at the top of the ramp, v ≈ 8.04 m/s
The time it takes the motorcycle to reach ground level from the top of the ramp, t, is given as follows;
h = h₀ + u·t + (1/2)·a·t²
h₀ = 2, u = 8.04×sin(20°), a = -9.81
When h = 0 (ground level), we have;
∴ h = 2+ 8.04×sin(20°)·t - (1/2)×9.81×t²
0 ≈ 2.75·t - 4.905·t² + 2
2.75·t - 4.905·t² + 2 = 0
By using a graphing calculator, we have, t = 0.978 or t = -0.42
At ground level, the time of flight, t ≈ 0.978 s
The horizontal distance the motorcycle travels, before landing, x = u × cos(θ) × t
∴ x = 8.04×cos(20 Degrees) × 0.978 = 7.3889
The horizontal distance the motorcycle travels, before landing, x ≈ 7.3889 m
Therefore, given that the horizontal distance the motorcycle travels in the air 7.3889 m < 10 m, therefore the motorcycle daredevil does not sail across the 10-m wide pool filled with hungry crocodiles
Explain why magnetic damping might not be effective on an object made of several thin conducting layers separated by insulation.
Answer:
The eddy currents will be very small.
Explanation:
An object made of several thin conducting layers separated by insulation may not be affected by magnetic damping because the eddy current produced in each layer due to induction will be very small and the opposing magnetic flux produced by the eddy currents will be very small.
What 3 things does the force of gravity depend on?
Answer:
Size of an object, and the distance between the objects.
When the mass of an object increases the force of gravity increases as well.
Explanation:
The magnitude of this force depends upon the mass of each object and the distance between the centers of the two objects. Mathematically, we say the force of gravity depends directly upon the masses of the objects and inversely upon the distance between the objects squared.
An organism that is only one cell big and has a nucleus is most likely a member of which kingdom?
Answer:
Protista
Explanation:
Taxonomy can be defined as the process of naming, classification and description of living organisms such as plants and animals. Thus, the biological classification of living organisms based on similarities or characteristics such as eyes, number of legs, etc., is generally referred to as taxonomy.
Basically, taxonomy helps scientist to have a good understanding and knowledge when studying various organisms.
Furthermore, the eight (8) biological classification (taxonomy) used for grouping and organizing organisms are; kingdom, domain, phylum, family, order, class, species and genus.
An organism that has only one cell, big and has a nucleus is most likely a member of Protista. Thus, a Protista such as euglena, paramecium, amoeba, etc., have a nucleus and are unicellular.
A unicellular organism refers to a living organism that possess a single-cell while a multicellular organism has many (multiple) cells.
A 4.04 kg block slides down a smooth, frictionless plane having an inclination of 30◦. The acceleration of gravity is 9.8 m/s^2. The acceleration of the plane is 4.9
What is the magnitude of the perpendicular force that the block exerts on the surface of the plane at a distance of 2.37 m down the incline?
Answer in units of N.
Answer:
Explanation:
What a lot of words to solve such a simple problem! The perpendicular force is the one that is pushing straight down on the plane. There is no side to side movement here or friction acting on this dimension at all. Perpendicular force is the same as the weight of the block. That's it! Perpendicular force is also normal force which is the same thing as weight:
w = mg so
w = (4.04)(9.8) and
w = 4.0 × 10¹ N
The magnitude of the perpendicular force that the block exerts on the surface of the plane at a distance of 2.37 m down the incline plane is 34.3N
The given parameter are:
mass M = 4.04 kg
Angle of inclination = 30 degree
Acceleration due to gravity = 9.8 m/s^s
To calculate the magnitude of the perpendicular force that the block exerts on the surface of the plane at a distance of 2.37 m down the plane, The force will be the weight of the block which is equal to the normal reaction.
Normal N = mgcosФ
N = 4.04 x 9.8 x cos30
N = 34.28 Newtons
At all point in the plane, the magnitude of the perpendicular force that the block exerts on the surface of the plane will be the same.
Therefore, the magnitude of the perpendicular force that the block exerts on the surface of the plane at a distance of 2.37 m down the incline plane is 34.3N
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The density of dry air at room temperature and atmospheric pressure Is 1.2 kg m-3. What volume would 6 kg of dry air occupy under these conditions?
Answer:
V = 5 m³
Explanation:
The density of air, d = 1.2 kg/m³
Mass of the dry air, m = 6 kg
We need to find the volume o the gas. We know that, the density of an object is given by mass divided by its volume. So,
[tex]d=\dfrac{m}{V}\\\\V=\dfrac{m}{d}\\\\V=\dfrac{6}{1.2}\\\\V=5\ m^3[/tex]
So, the volume of the dry air is 5 m³.
