Answer:
Explanation:
reading of scale = reaction force of surface R
centripetal force = R - mg = m v² / R , m is mass , v is velocity and R is radius of the circular path .
R = mg + m v² / R
given ,
m v² / R = .80 mg
v² = .80 x g x R
= .8 x 9.8 x 9 = 70.56
v = 8.4 m /s
A 2 kg toy car moves at a speed of 5 m/s.
What is the kinetic energy of the car?
Answer:
The answer is 25 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]KE = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]KE = \frac{1}{2} \times 2 \times {5}^{2} \\ = 1 \times {5}^{2} [/tex]
We have the final answer as
25 JHope this helps you
When three people with a total mass of 2.00 x 102 kg step into their 1.200 x 103 kg car, the car’s
springs are compressed by 3.0 cm.
1.2.a. What is the spring constant of the car’s springs assuming they act as a single spring?
1.2.b. How far will the car lower if loaded with 3.00 x 102 kg rather than 2.00 x 102 kg
Answer:
a
[tex]k = 457333.3 N/m[/tex]
b
[tex]x_a =0.09\ m[/tex]
Explanation:
From the question we are told that
The total mass of three people is [tex]M = 2.00*10^{2} \ kg[/tex]
The mass of the car is [tex]m_c = 1.200 *10^{3} \ kg[/tex]
The compression of the car spring is [tex]x = 3 \ cm = 0.03 \ m[/tex]
Generally the spring constant is mathematically represented as
[tex]k = \frac{F}{x}[/tex]
Here F is the force exerted by the mass of three people and that of the car , this is mathematically represented as
=> [tex]F = (M +m_c) *g[/tex]
=> [tex]F = ([2.0*10^{2} ]+[ 1.200*10^{3}]) * 9.8[/tex]
=> [tex]F = 13720 \ N[/tex]
So
[tex]k = \frac{13720}{0.03}[/tex]
=> [tex]k = 457333.3 N/m[/tex]
Generally if the mass which the car is loaded with is [tex]m = 3.00*10^{2} \ kg[/tex]
Then the force experienced by the spring is
=> [tex]F_a = (m +m_c) *g[/tex]
=> [tex]F_a = (3.00*10^{3} + 1.200 *10^{3}) * 9.8[/tex]
=> [tex]F_a = 41160 \ N[/tex]
Generally from the above formula the compression is
[tex]x_a = \frac{F_a}{k}[/tex]
=> [tex]x_a = \frac{41160}{457333.3}[/tex]
=> [tex]x_a =0.09\ m[/tex]
Identify the following compounds as polar covalent or nonpolar covalent: HBr, Cl2, and H2O.
Answer:
HBr- polar covalent
Cl2 - nonpolar covalent
H2O - polar covalent
Explanation:
Covalent bonds are chemical bonds that holds atoms of elements in such a way that electrons are shared between the atoms. However, based on the electronegativity differences between elements, compounds can either be polar covalent or nonpolar covalent.
Polar covalent bonds are formed when electrons are unevenly shared between two atoms based on difference in their electronegativities i.e. the more electronegative atom pulls more of the electrons. For example, in the case of HBr and H2O, Bromine and Oxygen atoms are more electronegative, hence, they pull more electrons making the electron sharing unequal, hence, a POLAR COVALENT BOND forms.
Non polar covalent bonds, contrarily, occurs when electrons are shared equally or evenly. This is so because the atoms of the elements involved have the same electronegativity. For example, Cl2 contains two atoms of Chlorine (Cl), which has the same electronegativity, hence, electrons between the two atoms are shared equally to form a NONPOLAR COVALENT BOND
HBr is polar covalent, Cl₂ - nonpolar covalent and H₂O is polar covalent in nature.
What is a polar covalent bond?When atoms with differing electronegativities share electrons in a covalent link, the result is a polar covalent bond.
Consider the molecule of hydrogen chloride (HCl). In order to generate an inert gas electron configuration, each atom in HCl requires one extra electron.
Covalent bonds are chemical bonds that keep atoms of different elements together while sharing electrons.
Compounds can be polar covalent or nonpolar covalent depending on the electronegativity variations between components.
When electrons are unevenly divided between two atoms due to differences in their electronegativities, polar covalent connections are created.
The more electronegative atom draws more electrons. In the case of HBr and H2O, for example, the Bromine and Oxygen atoms are more electronegative,
Therefore they draw more electrons, causing the electron sharing to be uneven, resulting in the formation of a polar covalent bond.
Hence HBr is polar covalent, Cl₂ - nonpolar covalent and H₂O is polar covalent in nature.
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A circular coil of 185 turns and radius 4.50 cm is placed inside and coaxial to a solenoid with 350 turns/m. If the current in the solenoid is represented by the equation I = a(1 − e−bt) where a = 12.5 A and b = 2.10 s−1, determine the magnitude of the induced emf in the coil when t = 1.50 s.
Answer:
Magnitude of the induced emf is 11.62 V
Explanation:
Given:
No. of turns of the circular coil, N=185
Radius, R=4.50 cm=0.045 m
No. of turns of solenoid per meter(m), n=350
a=12.5 A
b=2.10 [tex]s^{-1}[/tex]
Now,
To determine the emf induced in the coil at t = 1.50 s:
The given equation is:
[tex]I=a(1-e^{-bt})[/tex]
Now,
[tex]B=\mu_{o}nI=\mu_{o}na(1-e^{-bt})[/tex]
[tex]\frac{dB}{dt}=\mu_{o}nabe^{-bt}[/tex]
Now, substituting the respective values:
[tex]\frac{dB}{dt}=-4\pi\times 10^{-7}\times 350\times 12.5\times 2.10e^{-2.10\times 1.50}[/tex]
[tex]\frac{dB}{dt}=0.988\ T/s[/tex]
Now,
[tex]emf=NA\frac{dB}{dt}[/tex]
where,
A=Area=[tex]\pi R^{2}[/tex]
Thus,
[tex]emf=185\times \pi\times (4.50\times 10^{-2})^{2}\times 11.545e^{-3.15}[/tex]
[tex]emf=11.62 V[/tex]
How much heat is needed to raise the temperature of an empty 2.0 x 101 kg vat made of
iron from 10.0ºC to 90.0ºC?
Answer:
Q = 7272 Kilojoules.
Explanation:
Given the following data;
Mass = 2.0*101kg = 202kg
Initial temperature, T1 = 10°C
Final temperature, T2 = 90°C
We know that the specific heat capacity of iron = 450J/kg°C
*To find the quantity of heat*
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat. m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.dt = T2 - T1
dt = 90 - 10
dt = 80°C
Substituting the values into the equation, we have;
[tex] Q = 202*450*80[/tex]
Q = 7272KJ or 7272000 Joules.
Upon being struck by 240-nm photons, a metal ejects electrons with a maximum kinetic energy of 2.97 eV. What is the work function of this metal?
Answer:
Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV
Explanation:
The work function of the metal metal can be found as follows:
Energy of Photon = Work Function + K.E
hc/λ = Work Function + K.E
Work Function = hc/λ - K.E
where,
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of photons = 240 nm = 2.4 x 10⁻⁷ m
K.E = Maximum Kinetic Energy = (2.97 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 4.752 x 10⁻¹⁹ J
Therefore,
Work Function = (6.625 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(2.4 x 10⁻⁷ m) - 4.752 x 10⁻¹⁹ J
Work Function = 8.281 x 10⁻¹⁹ J - 4.752 x 10⁻¹⁹ J
Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV
Help Help just answers what ever you think is right but hurry
Which statements accurately describe the greenhouse effect? Check all that apply.
It is caused by liquids on Earth’s surface.
It is caused by gases in Earth’s atmosphere.
It warms up Earth’s surface and the lower atmosphere.
It cools down Earth’s surface and the lower atmosphere.
It maintains Earth’s normal atmospheric pressure.
It maintains Earth’s normal range of temperatures.
Please be honest
Answer:
it is caused by gases in earths atmosphere. it warms up earhs surface and lower atmosphere.
Explanation:
from what i know, these seem like the only ones that apply.
When a box is placed on an inclined surface with no friction, it will:
Answer: With no friction, the box will accelerate down the ramp
Explanation:
why might someone buy a more expensive CFL intead of an incandescent light bulb ?
Answer:
Even though CFL are more expensive, they tend to last longer. Research proves that CFL uses 1/4 to 1/3 the same amount of energy to produce the same lighting as an incandescent light bulb (source: enhso.com)
Suppose you have a coffee mug with a circular cross section and vertical sides (uniform radius). What is its inside radius if it holds 370 g of coffee when filled to a depth of 5.50 cm?
Answer:
r = 4.62 cm
Explanation:
Mass of a coffee, m = 370 g
Height of the mug, h = 5.5 cm
We need to find the inside radius of the mug. Density of an object is equal to the mass per unit volume. It can be given by :
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{m}{\pi r^2 h}\\\\r=\sqrt{\dfrac{m}{\pi dh}}\\\\r=\sqrt{\dfrac{370\ g}{\pi \times 1\ g/cm^3\times 5.5\ cm}}\\\\r=4.62\ cm[/tex]
So, the inside radius is 4.62 cm.
A train starts from rest at station A and accelerates at 0.5 m/s 2 for 60 s. Afterwards it travels with a constant velocity for 15 min. It then decelerates at 1 m/s2 until it is brought to rest at station B. Determine the distance between the stations.
Answer:
d = 28,350 m.
Explanation:
We can divide the problem in 3 parts, according to the type of movement that train had:A distance traveled while the train was speeding up.A distance traveled at constant speed.A distance traveled while the train was slowing down.For the first part, we can get the distance traveled using the kinematic equation for the displacement, starting from rest, as follows:[tex]x_{1} = \frac{1}{2} * a * t^{2} = \frac{1}{2} *0.5m/s2* (60s)^{2} = 900 m. (1)[/tex]
In order to get the final speed at this distance, we can simply apply the definition of acceleration, in this way:[tex]v_{f1} = a* t = 0.5 m/s2 * 60 s = 30 m/s (2)[/tex]
Since the second part is traveled at a constant speed, we can find the displacement applying the definition of average velocity, as follows:[tex]x_{2} = v_{f1} * t = 30 m/s* 60 s* 15 = 27,000 m (3)[/tex]
Finally, as we know the value of the deceleration, and that the final velocity is zero from the givens, we can apply the following kinematic equation to get the displacement during the third stage:[tex]v_{f3}^{2} - v_{o3} ^{2} = 2* a_{3} * x_{3} (4)[/tex]
Replacing by the values and solving for x₃, we get:[tex]x_{3} = \frac{v_{o3}^{2}}{2*a_{3} } = \frac{(30m/s)^{2}}{2*1m/s2} = 450 m (5)[/tex]
The total distance d is just the sum of x₁, x₂ and x₃, from (1), (3) and (5), as follows:d = x₁ + x₂ + x₃ = 900 m + 27,000 m + 450 m = 28,350 m.A ball of mass 0.500 kg is carefully balanced on a shelf that is 2.70 m above the ground. What is its gravitational potential energy
Answer:
The gravitational potential energy of the ball is 13.23 J.
Explanation:
Given;
mass of the ball, m = 0.5 kg
height of the shelf, h = 2.7 m
The gravitational potential energy is given by;
P.E = mgh
where;
m is mass of the ball
g is acceleration due to gravity = 9.8 m/s²
h is height of the ball
Substitute the givens and solve for gravitational potential energy;
PE = (0.5 x 9.8 x 2.7)
P.E = 13.23 J
Therefore, the gravitational potential energy of the ball is 13.23 J.
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Answer:
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Explanation:
Answer:
okay
In 3 meters a person running 0.5 m/s accelerates 1.2 m/s 2. How fast were they going afterward? Choose the right equation for this word problem from below.
Answer:
2.72 m/s
Explanation:
In 3 meters a person running 0.5 m/s accelerates 1.2 m/s².
It means,
Distance, s = 3 m
Initial velocity, u = 0.5 m/s
Acceleration, a = 1.2 m/s²
We need to find the final velocity of the person. Using equation of motion to find it as follows :
[tex]v^2-u^2=2as\\\\v^2=2as+u^2\\\\v^2=2\times 1.2\times 3+(0.5)^2\\\\v=2.72\ m/s[/tex]
So, the final velocity of the person is 2.72 m/s.
a force of 100.0N is appliesd to an object of mass 85.0kg. what is the object acceleration
Answer:
1.18 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{100}{85} = \frac{20}{17} \\ = 1.176470...[/tex]
We have the final answer as
1.18 m/s²Hope this helps you
A good alternative to sit ups is
Answer:
Planks, barbell rollouts, and swiss ball pikes
Explanation:
Pushing a door closed is an example of force. true or false
Answer:
True
Explanation:
I am not 100% on the answer for this question but i hope it was right
Pushing is a force so that statement is true
Which best describes a characteristic of an adiabatic process?
Answer:
Can you please provide the choices? For now this is all I can give you.Explanation:
In thermodynamics, an adiabatic process is a type of thermodynamic process which occurs without transferring heat or mass between the system and its surroundings.Unlike an isothermal process, an adiabatic process transfers energy to the surroundings only as work. It also conceptually supports the theory used to explain the first law of thermodynamics and is therefore a key thermodynamic concept.
The system takes in heat but does not release it. If an adiabatic process is reversible, there is no change in entropy; otherwise, there is a rise in entropy, or degree of disorder.
What is adiabatic process?
A thermodynamic process known as an adiabatic process takes place when there is no exchange of mass or heat between the system and its surroundings.
An adiabatic process only transfers energy to the environment as work, in contrast to an isothermal process.
The system's overall heat remains constant since there is no heat exchange with the environment.
It is a fundamental idea in thermodynamics and theoretically supports the theory that underlies the first law of thermodynamics.
Therefore, no heat flow in and out of system, which is a characteristic of an adiabatic process.
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How does radiation differ from conduction? (4 points)
A force of 10 newtons toward the right is exerted on a
wooden crate initially moving to the right on a horizontal
wooden floor. The crate weighs 25 newtons.
1. Calculate the magnitude of the force of friction between the crate and the floor.
2. What is the magnitude of the net force acting on the crate?
Answer:
Explanation:
coefficient of kinetic friction of wooden floor μ = .4
force of friction = μ R , R is reaction force of floor
R = mg = weight of body
R = 25 N
force of friction = .4 x 25 = 10 N
Net force on the crate = 10 - 10 = zero .
Net force on the body will be nil.
A wheel turns through 5.5 revolutions while being accelerated from rest at 20rpm/s.(a) What is the final angular speed ? (b) How long does it take to turn the 5.5 revolutions?
Answer:
(a) The final angular speed is 12.05 rad/s
(b) The time taken to turn 5.5 revolutions is 5.74 s
Explanation:
Given;
number of revolutions, θ = 5.5 revolutions
acceleration of the wheel, α = 20 rpm/s
number of revolutions in radian is given as;
θ = 5.5 x 2π = 34.562 rad
angular acceleration in rad/s² is given as;
[tex]\alpha = \frac{20 \ rev}{min} *\frac{1}{s} *(\frac{2\pi \ rad}{1 \ rev } *\frac{1 \ min}{60 \ s}) \\\\\alpha = 2.1 \ rad/s^2[/tex]
(a)
The final angular speed is given as;
[tex]\omega _f^2 = \omega_i ^2 + 2\alpha \theta\\\\\omega _f^2 = 0 + 2\alpha \theta\\\\\omega _f^2 = 2\alpha \theta\\\\\omega _f = \sqrt{2\alpha \theta}\\\\ \omega _f = \sqrt{2(2.1) (34.562)}\\\\ \omega _f = 12.05 \ rad/s[/tex]
(b) the time taken to turn 5.5 revolutions is given as
[tex]\omega _f = \omega _i + \alpha t\\\\12.05 = 0 + 2.1t\\\\t = \frac{12.05}{2.1} \\\\t = 5.74 \ s[/tex]
Discuss the pros and cons of one of the examples of variations in family life – cohabitation, single-parent households, same-sex couples.
Answer:
a pro to single parent house holds is no favorite parent and a chance to have a better bond with your child a con could be money trouble or jealousy of others with to parents. a pro to same sex couples could be the children could learn to be accepting of others and their differences a con could be the children might be bullied by trashy homophobes at their school and other places for have same sex parents. i did both so you could chose
A pulley is in the form of a uniform solid cylinder of radius 7cm and mass 2kg. One end of a very light rope is fixed to wind the pulley and the other end is
free. When we pull the free end of the rope the pulley starts rotating from rest and accelerates uniformly. If the angular acceleration is 100rad/s so the
tangential acceleration of the rope is:
Chọn một:
a.
200 N
b.
49 N
C.
0.49 N
d.
7N
A transformer has an output coil with 6 times as many turns as the input coil. If the input frequency is f then the output frequency will be:_______
a. 9f
b. 6f
c. 1/6 f
d. f
Answer:
d. f
Explanation:
Based on the principle of operation of transformer, when a.c voltage is applied at the terminal of the primary coil (input coil), an alternating magnetic flux is produced in the iron core which links the secondary coil (output coil).
Also, an alternating e.m.f of the same frequency as that of primary coil (input coil) will be induced in the secondary coil (output coil) by mutual inductance.
Thus, If the input frequency is "f" then the output frequency will be "f" (since the frequency will be the same).
The correct option is "D"
A truck goes 5500 meters in 25 minutes, what is the speed of the truck?
Answer:
220
Explanation:
5500 divided by 25 is 220
Answer:
it's easy the answer is 500 just multiple 500 times 25 and you will get 5500
where does a solid material go when a solution is made
Answer:
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Explanation:
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I REALLY NEED HELP!!! I WILL EVEN VENMO!
The free-body diagram shown above represents a car being pulled by a towing cable. In the diagram what is the gravitational force acting on the car?
I NEED WORK SHOWN!!!
Answer:
can u buy me a giftcard ill have this done in no time
Explanation:
Which energy source has no greenhouse gas emissions or health impacts on humans, but is only
available in certain geographic locations?
Answer: geothermal
Explanation:
The geothermal energy source has no greenhouse gas emissions or health impacts on humans.
What is geothermal energy?Geothermal energy can be described as the thermal energy in the Earth's crust which arises from the formation of the planet and from the radioactive decay of materials.
The high temperature in Earth's interior cause rock to melt and solid mantle to behave plastically. The mantle convects upward since it is lighter than the surrounding rock. Temperatures at the core-mantle boundary reach over 4000 °C.
Geothermal heating can use water from hot springs and geothermal power means the generation of electricity from geothermal energy, which has gained importance.
Earth's geothermal resources are more than adequate to supply humanity's energy needs, although a small fraction is currently being profitably exploited, commonly in areas near tectonic plate boundaries.
The greenhouse gas emissions of geothermal stations are on average 45 g of CO₂ per kWh of electricity or less than 5% of that of conventional coal-fired plants.
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An object accelerates 2.0 m/s2 when a force of 25.0 Newtons is applied to it. What is the mass of the object?
Answer:
12.5 kgExplanation:
The mass of the object can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{25}{2} \\ [/tex]
We have the final answer as
12.5 kgHope this helps you
An object is projected from the ground with an upward speed of ų m/s has a speed of 23m/s when it is at a height of 5m above the ground .Use work energy principle to determine the initial speed u.
Answer:
25.08m/s
Explanation:
mgh1 + 0.5mv1² = mgh2 + 0.5mv2²
h1 = 0m
v1 = u
h2 = 5m
v2 = 23m/s
putting the values into the formula above;
m(10)(0) + 0.5m(u²) = m(10)(5) + 0.5m(23²)
0 + 0.5mu² = 50m + 264.5m
0.5mu² = 314.5m
dividing through by m
0.5u² = 314.5
u² = 629
u = 25.08m/s
Therefore, the initial speed "u" = 25m/s