Answer: B
D makes no sense because energy is created so we can remove that. C also makes no sense because if energy is not created how did it get destroyed if there's no energy in the first place. This leaves us with a and B the correct answer is B because energy is created and cannot be destroyed.
A uniform rod is hung at one end and is partially submerged in water. If the density of the rod is 5/9 that of water, find the fraction of the length of the rod above water
Answer:
[tex]\frac{y}{L}[/tex] = 0.66
Hence, the fraction of the length of the rod above water = [tex]\frac{y}{L}[/tex] = 0.66
and fraction of the length of the rod submerged in water = 1 - [tex]\frac{y}{L}[/tex] = 1 - 0.66 = 0.34
Explanation:
Data given:
Density of the rod = 5/9 of the density of the water.
Let's denote density of Water with w
And density of rod with r
So,
r = 5/9 x w
Required:
Fraction of the length of the rod above water.
Let's denote total length of the rod with L
and length of the rod above with = y
Let's denote the density of rod = r
And density of water = w
So, the required is:
Fraction of the length of the rod above water = y/L
y/L = ?
In order to find this, we first need to find out the all type of forces acting upon the rod.
We know that, a body will come to equilibrium if the net torque acting upon a body is zero.
As, we know
F = ma
Density = m/v
m = Density x volume
Volume = Area x length = X ( L-y)
So, let's say X is the area of the cross section of the rod, so the forces acting upon it are:
F = mg
F = (Density x volume) x g
g = gravitational acceleration
F1 = X(L-y) x w x g (Force on the length of the rod submerged in water)
where,
X (L-y) = volume
w = density of water.
Another force acting upon it is:
F = mg
F2 = X x L x r x g
Now, the torques acting upon the body:
T1 + T2 = 0
F1 ( y + [tex](\frac{L-y}{2})[/tex] ) g sinФ - F2 x ([tex]\frac{L}{2}[/tex]) x gsinФ = 0
plug in the equations of F1 and F2 into the above equation and after simplification, we get:
[tex](L^{2} - y^{2} ) . w[/tex] = [tex]L^{2}[/tex] . r
where, w is the density of water and r is the density of rod.
As we know that,
r = 5/9 x w
So,
[tex](L^{2} - y^{2} ) . w[/tex] = [tex]L^{2}[/tex] . 5/9 x w
Hence,
[tex](L^{2} - y^{2} )[/tex] = [tex]\frac{5L^{2} }{9}[/tex]
[tex]\frac{L^{2} - y^{2} }{L^{2} }[/tex] = [tex]\frac{5}{9}[/tex]
Taking [tex]L^{2}[/tex] common and solving for [tex]\frac{y}{L}[/tex], we will get
[tex]\frac{y}{L}[/tex] = 0.66
Hence, the fraction of the length of the rod above water = [tex]\frac{y}{L}[/tex] = 0.66
and fraction of the length of the rod submerged in water = 1 - [tex]\frac{y}{L}[/tex] = 1 - 0.66 = 0.34
What happens at the end of most cold currents?
Answer:
Ocean currents act as conveyer belts of warm and cold water, sending heat toward the polar regions and helping tropical areas cool off, thus influencing both weather and climate.
Explanation:
Essential Questions: What does the particle theory tell us about the nature of matter? How does
each state of matter behave?
sowwie :( i need points
Explanation:
Caca box like fish no earnings play like caca
400 points in arena youa have none thats Why I wonder
Answer:
I actually have 20000 arena points thank you very much
Answer: Caca means in French lol.
describe the importance of the neutron in a atomic nuclei
Neutrons are required for the stability of nuclei, with the exception of the single-proton hydrogen nucleus. Neutrons are produced copiously in nuclear fission and fusion. They are a primary contributor to the nucleosynthesis of chemical elements within stars through fission, fusion, and neutron capture processes.
Hope it helps!
(b)
The total power input to the leaf blower is 750 W.
The useful power output of the leaf blower is 360 W.
Calculate the efficiency of the leat blower.
The efficiency of the leaf blow is 48%.
How can we find the efficiency of the leaf blower?E = m×c×ФHere, E = Energy transferred
m = Mass
Ф = Temperature change
efficiency = (Useful energy out / Total energy in ) × 100efficiency = (Useful power out / Total power in ) × 100E = P × tHere, E = Energy transferred
P = Power
t = time
v = f ×∧Here, v = speed
f = frequency
∧ = wavelength
Substitute into the time equation,Efficiency = (Useful power out / Total power in ) = 360/750 = 0.48
Convert it to percentage = 0.48 × 100 = 48%So, the efficiency of the leaf blower is 48%.
To learn more about efficiency, refer to: https://brainly.com/question/21305967
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Why does liquid water boil away when exposed to the Martian atmosphere?
a. the surface of Mars is much hotter than the surface of Earth.
b. it is quickly absorbed into the dry soil.
c. radiation from the Sun passes through Mars' atmosphere and boils the water.
d. the low air pressure lowers the boiling point
Answer: d. the low air pressure lowers the boiling point
Explanation:
Note that there cannot be less than 6.1 millibars of liquid water. This fact is important because the Martian surface atmospheric pressure hovers just below that value. Any water that could form from melting water on a warm afternoon will easily vanish into the desiccated Martian atmosphere.
4. What is the electric field strength (E) at a distance of 0.50 m from a 1.00×10°C charge?
Answer:
3.6*10¹⁰N/C
Explanation:
The formula for Electric field strength is expressed as:
E = kQ/r²
k is the coulombs constant = 9*10^9Nm²/C²
Q is the charge = 1.00×10°C
r is the distance = 0.50m
Substitute the parameters into the formula as shown:
E = kQ/r²
E = 9*10^9(1)/0.5²
E = 9*10^9/0.25
E = 36*10^9
E = 3.6*10¹⁰N/C
Hence the electric field strength is 3.6*10¹⁰N/C
A circular space station of radius 100 m rotates twice each minute.
a. Find the acceleration of an astronaut standing at the outer edge of the space
station. How many g's does she feel? (1g=9.8ms2)
b. What must the period of rotation of the space station be in order for astronauts
at the outer edge to experience the same acceleration as on earth?
The space station completes 2 revolutions each minute, so that it traverses a distance of 2π (100 m) = 200π m each minute, giving it a linear/tangential speed of
v = (200π m) / (60 s) ≈ 10.472 m/s
(a) The astronaut would experience an acceleration of
a = v ² / (100 m) ≈ 1.09662 m/s² ≈ 0.1119g ≈ 0.11g
(b) Now you want to find the period T such that a = g. This would mean the astronaut has a tangential speed of
v = (200π m) / T
so that her centripetal/radial acceleration would match g :
a = g = ((200π m) / T )² / (100 m)
Solve for T :
(100 m) g = (400π ² m²) / T ²
T ² = (400π ² m²) / ((100 m) g) = (4π ² m)/g
T = √((4π ² m) / (9.8 m/s²)) ≈ 2π √(0.102 s²) ≈ 2.007 s ≈ 2.0 s
A 4 kg bowling bowl is sitting on a table 1 meter off the ground. How much potential energy does it have?
Answer:
[tex]\huge\boxed{\sf P.E. = 39.2\ Joules}[/tex]
Explanation:
Given Data:
Mass = m = 4 kg
Acceleration due to gravity = g = 9.8 m/s²
Height = h = 1 m
Required:
Potential Energy = P.E. = ?
Formula:
P.E. = mgh
Solution:
P.E. = (4)(9.8)(1)
P.E. = 39.2 Joules
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807Why do dumplings cook faster in oil than water?
Answer:
oil heats faster
Explanation:
that's all
Answer:
Oil gets hotter faster or something
A football player kicks a ball with a mass of 0.5 kg. The average acceleration of the football was 15 m/s/s. How much force did the kicker apply to the football?
A. 15.5 N
B. 7.5 N
C. 14.5 N
D. 30 N
Answer:
Explanation:
F = m*a = (0.5)*15 = 7.5 N
What is the force needed to accelerate a 10 kg object at 2 m/s??
Answer:
5 newtons
Explanation:
Just divide them
please help thank you
which of the following statements BEST describes the difference between an atom and an ion ?
Answer:
well the correct answer is
d. An atom contains equal numbers of protons and electrons whereas an ion contains unequal numbers of protons and electrons .Explanation:
A charged atom is known as an ion, well it can be negative as well as positive charge.
if atom has more protons than electrons then it get positively charged and known as cationif the atom has more electrons that the number of protons then the atom get negatively charged and known as anionThe area of the foundation of a square house is 840 ft. Find
the side length of the foundation of the house to nearest whole
number
Answer:
210 ft.
Explanation:
Since a square has 4 sides and all sides are equal, just do 210 divided by 4.
Calculate the volume of 1280 kilograms of aluminium if the density is 2700kg/m3
Answer:
0.47m3
Explanation:
Volume = Mass / Density
In this case:
Mass - 1280 kg
Density - 2700kg/m3
1280 / 2700 = 0.4740741m3
When this is rounded off ( 2 d.p ):
0.47 m3
HOPE THIS HELPED
Diffusion and osmosis are forms of passive transport.
True
False
Answer:
True. Diffusion and osmosis are forms of passive transport.
Explanation:
In diffusion, particles move from an area of higher concentration to one of lower concentration until equilibrium is reached.
In osmosis, a semipermeable membrane is present, so only the solvent molecules are free to move to equalize concentration.
Answer:
100% true
Explanation:
Simple diffusion and osmosis are both forms of passive transport and require none of the cell's ATP energy. Example of diffusion: Gas Exchange A biological example of diffusion is the gas exchange that occurs during respiration within the human body.
in 1-2 complete sentences define "opportunity cost " in your own words
Answer:
Here you go, hope this helps! :)
Explanation:
Opportunity cost is the value of the next best thing you give up whenever you make a decision. It is "the loss of potential gain from other alternatives when one alternative is chosen". ... For example, opportunity cost is how much leisure time we give up to work.
le Which describes how light waves can interact with wood?
(14 Points)
O A. absorption and reflection
O B. diffraction and transmission
0 C. reflection and refraction
O D. transmission and refraction
Answer: A ,absorption and reflection
Explanation
Absorption and reflection are the two phenomena which describe how the light waves can interact with the wood. Thus, the correct option is A.
What is Absorption and reflection of light?Light absorption is a process through which light is absorbed and converted into different form of energy. An example of absorption of light is the process of photosynthesis which takes place in plants. However, light absorption does not occur exclusively in the plants, but in all the creatures and inorganic substances present on this planet.
When a ray of light approaches a smooth polished surface such as a metal surface and the light ray bounces back, it is called as the reflection of light. The incident light ray which lands on the surface is reflected off the surface. The ray that bounces back from the surface is called the reflected ray.
Therefore, the correct option is A.
Learn more about Light waves here:
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Hey Motors and lamps both use...
electricity that isn't moving
electric current
Both a and b
Answer:
both
Explanation:
You use 35 J of energy to move a 7.0N object.How far did it move
Answer:
5 metres
Explanation:
Work Done = Force x Distance
So Distance = Work done ÷ Force
= 35 ÷ 7.0
= 5 metres
PLEASE ANSWER QUESTION 7!!!! PLEASE
Answer:
Explanation:
The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them. This means that the force of gravity increases with mass, but decreases with increasing distance between objects
so a option is correct
A block of mass m is hung from the ceiling by the system of massless springs consisting of two layers. The upper layer consists of 3 strings in paralle, and the lower layer consists of 2 strings in parallel. The horizontal bar between the two layers has negligible mass. The force constants of all springs are k. Calculate the period of the vertical oscillations of the block.
Answer:
T₀ = 2π [tex]\sqrt{\frac{m}{k} }[/tex] T = [tex]\sqrt{\frac{5}{6} }[/tex] T₀
Explanation:
When the block is oscillating it forms a simple harmonic motion, which in the case of a spring and a mass has an angular velocity
w = [tex]\sqrt{k/m}[/tex]
To apply this formula to our case, let's look for the equivalent constant of the springs.
Let's start with the springs in parallels.
* the three springs in the upper part, when stretched, lengthen the same distance, therefore the total force is
F_total = F₁ + F₂ + F₃
the springs fulfill Hooke's law and indicate that the spring constant is the same for all three,
F_total = - k x - k x - kx = -3k x
therefore the equivalent constant for the combination of the springs at the top is
k₁ = 3 k
* the two springs at the bottom
following the same reasoning the force at the bottom is
F_total2 = - 2 k x
the equivalent constant at the bottom is
k₂ = 2 k
now let's work the two springs are equivalent that are in series
the top spring is stretched by an amount x₁ and the bottom spring is stretched x₂
x₂ = x -x₁
x₂ + x₁ = x
if we consider that the springs have no masses we can use Hooke's law
[tex]-\frac{F_{1} }{k_{1} } - \frac{F_{2}}{k_{2} } = \frac{F}{k_{eq} }[/tex]
therefore the equivalent constant is the series combination is
[tex]\frac{1}{k_{eq} } = \frac{1}{k_{1} } + \frac{1}{k_{2} }[/tex]
we substitute the values
\frac{1}{k_{eq} } = \frac{1}{3k } + \frac{1}{2k }
\frac{1}{k_{eq} } = \frac{5}{6k} }
k_eq = [tex]\frac{6k}{5}[/tex]
therefore the angular velocity is
w = [tex]\sqrt{\frac{6k}{5m} }[/tex]
angular velocity, frequency, and period are related
w = 2π f = 2π / T
T = 2π / w
T = 2π [tex]\sqrt{\frac{5m}{6k} }[/tex]
T₀ = 2π [tex]\sqrt{\frac{m}{k} }[/tex]
T = [tex]\sqrt{\frac{5}{6} }[/tex] T₀
If the angle between the net force and the displacement of an
object is greater than 90 degrees, then which option holds
true?
aThe object stops
b Kinetic energy decreases
C Kinetic energy increases
d Kinetic energy remains the same
Answer: kinetic energy decreases
Explanation:
When the angle between the net force and the displacement of an
object is greater than 90 degree, the Kinetic energy decreases.
The work done by a net force in moving an object over a given distance is given as;
[tex]W = F \times d \ cos(\theta)[/tex]
where;
θ is the angle between the net force and the displacementThe value of cos(θ) decreases from 0 to 180, consequently, the value of work-done will decrease as well.
Based on work-energy theorem, the work done on the object is equal to kinetic energy of the object.
[tex]W = K.E[/tex]
Thus, we can conclude that when the angle increases, the Kinetic energy decreases.
Learn more about kinetic energy here:https://brainly.com/question/10063455
Determine the absolute pressure on the bottom of a swimming pool 30.0 mm by 8.4 mm whose uniform depth is 1.9 mm .
Answer:
=101343.62N/m^2
Explanation:
absolute pressure on the bottom of a swimming pool= atmospheric pressure +( 2 ×ρ ×g)
( 2 ×ρ ×g)= guage pressure
atmospheric pressure= 101325pa
h= height= 1.9 mm = 1.9×10^-3m
ρ = density of water
= 1000kg/m^3
g= acceleration due to gravity= 9.8m/s^2
Then substitute, we have
absolute pressure on the bottom of a swimming pool= 101325+ [0.0019 ×1000 × 9.8)]
=101343.62N/m^2
Hence, the absolute pressure on the bottom of a swimming pool is =101343.62N/m^2
The heat vaporization for methyl alcohol is 1100 kj/kg. It is 2257 KJ/Kg for water. Thus means that______________.
A) these are the amounts of energy to change temperature 1 degree C. required for these substances
B) Methyl alcohol requires less than half as much energy per kg to evaporate than water doe
C) water will get twice as ot as methyl alcohol during vaporization.
d) when alcohol and water evaporate they release 2,2 kj and 2257 kj of energy for every kg respectivly
Please hurry! I'm being timed!
Answer: B) Methyl alcohol requires less than half as much energy per kg to evaporate than water does
Explanation:
Latent heat of vaporization is the amount of heat required to convert 1 kilo gram of liquid into its vapor state without change in its temperature.
Heat of vaporization is more for water than for methyl alcohol which means more heat is required to convert from liquid to vapour form.
As the Heat of vaporization for methyl alcohol (1100) is almost half as that of Heat of vaporization for water (2257) , it means Methyl alcohol requires less than half as much energy per kg to evaporate than water does.
Need help y’all ASAP please...physics
Answer:
t = 3/8 seconds
Explanation:
h=-16t^2 - 10t+6
h= 0 when it hits the ground
0=-16t^2 - 10t+6
factor out a -2
0= -2(8t^2 +5t -3)
divide by -2
0 = (8t^2 +5t -3)
factor
0=(8t-3) (t+1)
using the zero product property
8t-3 = 0 t+1 =0
8t = 3 t= -1
t = 3/8 t= -1
t cannot be negative ( no negative time)
t = 3/8 seconds
Create a following distance greater than 3 seconds ahead when_______. a driver behind you is trying to pass you are not in a hurry there is no traffic on the road you are traveling in front of a motorcycle.
Answer:
option (a)
Explanation:
Maintaining distance while driving in traffic can avoid the chances of an accident.
When the driver is behind you is trying to pass you to avoid the collision you should maintain a distance greater than 3 sec.
Hence, option (a) is correct.
Answer:
a driver behind your vehicle is trying to pass you
Explanation:
took test and checked
Victor covers 210 km by car at a speed of 70 km/hr. find the time taken to cover this distance.
Answer:
3 hrs
Explanation:
the distance covered by victor= 210 km
speed= 70 km/hrs
so, 70×3= 210
so the answer is 3 hrs
BTW im a small kid so don't just right away say the explanation sucks and the subject physics is not yet started in my grade.
edit: don't give me brainless answer plz.
A 9.0 × 10 3 kg satellite orbits the earth at the distance of 2.56 × 10 7 m from Earth's surface. What is its period?
Answer:
1.6537 * 10^9
Explanation:
Given that :
Distance (r) = 2.56 × 10^7 m
Using the relation from Kepler's third law of motion :
T2 = [ 4* pi^2/ G (M1 + M2) ]r^3
M1 = mass of earth = 5.97 *10^24
M2 = Mass of satellite = 9.0 × 10^3 kg
G = Gravitational constant = 6.67 *10^-11
T2 = [ (4 x 3.14^2) / 6.67 x 10^-11 ( 9 x 10^3 + 5.97 x 10^24)]/ (2.56 x 10^7)^3
= 1.6537 * 10^9