Answer:
"the plants had already started growing."
Explanation:
I think this is the answer because the definition of a dependent variable is the variable that is being affected by the change. Since the plants had already started growing BECAUSE of "They ran out of the farmer's compost, so
some of the plants received that compost
when the seeds were planted and other
plants got hardware store compost after
the plants had already started growing."
Sorry if I am wrong, I am just a 4th grader, pls don't hate on me, I am just trying to help :)
Answer:
It's compost
Explanation:
In case you needed the dependent variable, its the amount of plant growth
Noticing large amounts of algal growth in her small farm pond, a farmer adds about 20 grass carp to feed on the abundant algae and plants. After several years, the carp grow large, exceeding 20 pounds each in size. Late one summer, the farmer notices that the carp and most of the other fish are dead. The water also smells very bad. Which one of the following is the most likely explanation for the death of these fish?
A. the algae overgrew the pond and produced toxic levels of ozone
B. carbon dioxide released by the carp and algae eventually suffocated the fish in the pond
C. the large carp grew so large that they could not get enough oxygen
D. bacteria feeding on the large volume of carp feces depleted the oxygen
Answer:
D. bacteria feeding on the large volume of carp feces depleted the oxygen
Explanation:
In the context, it is given that in a small farm pond, the owner added 20 grass carp and feed them with the abundant plants and algae that is found on her pond. The carp grew large after many years but one summer the owner found the grass carps along with other fishes were dead.
The most possible explanation for the dead of the fishes in the pond because the bacteria feeds on the carp feces which depletes the dissolved oxygen present in the water. Thus the fishes could not breathe and were finally dead.
Therefore, the correct option is (D).
From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What is the receding speed of the star? c = 3x10^5 km/s
Answer:
[tex]v=-4.93\times 10^{5}~m/s[/tex] [negative sign denotes that it is moving away]
Explanation:
Actual wavelength of hydrogen spectral lines, [tex]\lambda=121.6~nm[/tex]
Apparent wavelength of hydrogen spectral lines from a star, [tex]\lambda'=121.8~nm[/tex]
So, shift in wavelength:
[tex]\Delta \lambda=\lambda'-\lambda[/tex]
[tex]\Delta \lambda=121.8-121.6[/tex]
[tex]\Delta \lambda=0.2~nm[/tex]
Using Doppler's shift:
[tex]\frac{\Delta \lambda}{\lambda} =-\frac{v}{c}[/tex]
[tex]\frac{0.2}{121.6} =-\frac{v}{3\times 10^8}[/tex]
[tex]v=-4.93\times 10^{5}~m/s[/tex] [negative sign denotes that it is moving away]
Calculate the distance travelled by the car in part Q use the equation distance travelled= average speed x time
Explanation:
distance travelled = average speed x time
=30m/s*100s
=3000m
Answer:
3000m
Explanation:
30m/s*100s
3000m
The core of transformer is laminated.......
a.to reduce the loss of energy in the form of heat across the transformer
b.to reduce the voltage of AC
c.to decrease the voltage of AC
d. to change the maginetic flux
Answer:
A. to reduce the loss of energy in the form of heat across the transformer
Explanation:
The core of the transformer is laminated to minimise the energy as they interfere with the efficient transfer of energy from the primary coil to the secondary one. The eddy currents cause energy to be lost from the transformer as they heat up the core - meaning that electrical energy is being wasted as heat.
A car is moving at 30km/h. What is its speed in m/s? Give your answer to 2 significant figures.
Explanation is in the attachment
hope it is helpful to you
While visiting the beach, you enjoy the warm ocean water, but the sand burns your feet. That night you walk along the beach and notice that the sand is colder than the ocean water. Why?
Group of answer choices
It takes a long time for sand to heat up, but it cools down very quickly. Water takes a short time to heat up and cool down.
Since sand can heat up quickly, it will also cool off quickly. But water takes a long time to heat up and cool down.
Water is naturally colder than sand.
Sand is naturally colder than water.
The answer would be B..
Since sand can heat up quickly, it will also cool off quickly. But water takes a long time to heat up and cool down.
Quickly pls!!! A wave with a wavelength of 0.5 m moves with a speed of 1.5 m/s. What is the frequency of the wave?
A. 2.0 Hz
B. 1.0 Hz
C. 0.33 Hz
D. 3.0 Hz
How did the English bill of rights impact the colonists views of government?
The English Bill of Rights helped to shape the colonists' views of government by promoting the ideas of individual liberty, representative democracy, and limited government.
What is English bill of rights?The English Bill of Rights is a document that was passed by the Parliament of England in 1689. It was a key moment in the development of modern democratic government, as it established certain rights and protections for English citizens, such as the right to bear arms, the right to a fair trial, and the prohibition of cruel and unusual punishment.
The English Bill of Rights also limited the power of the monarchy, requiring the king or queen to obtain the consent of Parliament before levying taxes or making other important decisions. Its influence can still be seen today in many democracies around the world.
Learn more about English bill of rights, here:
https://brainly.com/question/20986147
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A distant planet with a mass of (7.2000x10^26) has a moon with a mass of (5.0000x10^23). The distance between the planet and the moon is (6.10x10^11). What is the gravitational force between the two objects?
A distant planet with a mass of (7.2000x10^26) has a moon with a mass of (5.0000x10^23). The distance between the planet and the moon is (6.10x10^11). What is the gravitational force between the two objects?
Answer:
Explanation:
This is a simple gravitational force problem using the equation:
[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] where F is the gravitational force, G is the universal gravitational constant, the m's are the masses of the2 objects, and r is the distance between the centers of the masses. I am going to state G to 3 sig fig's so that is the number of sig fig's we will have in our answer. If we are solving for the gravitational force, we can fill in everything else where it goes. Keep in mind that I am NOT rounding until the very end, even when I show some simplification before the final answer.
Filling in:
[tex]F_g=\frac{(6.67*19^{-11})(7.2000*10^{26})(5.0000*10^{23})}{(6.10*10^{11})^2}[/tex] I'm going to do the math on the top and then on the bottom and divide at the end.
[tex]F_g=\frac{2.4012*10^{40}}{3.721*10^{23}}[/tex] and now when I divide I will express my answer to the correct number of sig dig's:
[tex]Fg=[/tex] 6.45 × 10¹⁶ N
is acting on an object that is constrained to move along the x-axis. If the force moves the object 3m, from the origin, what is the potential energy difference due to this force acting on the object
Answer:
U = - ∫ F dx
U = - 3F₀
Explanation:
Force and potential energy are related
F = [tex]- \frac{dU}{dx}[/tex]
dU = - F dx
∫ dU = - ∫ F dx
U- U₀ = - ∫ F dx
to solve the problem we must know the form of the force, if we assume that F = F₀ and U₀ = 0 for x = 0
U = - F₀ 3
Please help me. Please help me.
Answer:
Make a nice powerpoint and think about the question
Explanation:
Its easier than you think :)
three condensers are connected in series across a 150 volt supply, the voltages across them are 40,50 and 60 volts respectively, and the charge on each condenser is 6×10^-8 c.calculate (a) the capacitance of each condenser (b)the effective capacitance of the combination
Answer:
(a) 1.5 nF, 1.2 nF, 1 nF
(b) 0.4 nF
Explanation:
V = 150 V
V' = 40 V, V'' = 50 V, V''' = 60 V, q = 6 x 10^-8 C
(a) C' = q/V' = 6 x 10^-8 / 40 = 1.5 x 10^-9 F
C'' = q/V'' = 6 x 10^-8 / 50 = 1.2 x 10^-9 F
C''' = q/V''' = 6 x 10^-8 / 60 = 1 x 10^-9 F
(b) The effective capacitance is
[tex]\frac{1}{C}=\frac{1}{C'}+\frac{1}{C''}+\frac{1}{C'''}\\\\\frac{1}{C}=\frac{10^9}{1.5}+\frac{10^9}{1.2}+\frac{10^9}{1}\\\\C = 0.4\times 10^{-9} F[/tex]
Example Problem
The potential energy of an object is given by U(x) = 8x2 - x4, where U is in joules and x is in
(a) Determine the force acting on this object.
(b) At what positions is this object in equilibrium?
(c) Which of these equilibrium positions are stable and which are unstable?
metres.
111 Unit 2 Concepts and Definitions Prof Mark Lester
Exam Part B Example
A neutron of mass m moving with velocity v collides head-on and elastically with a stationary nucleus of mass M.
(a) Show that the velocity of the nucleus after the collision, U, is given by
U= 2m v (m+M)
(b) Hence show that the neutron loses a fraction f of its energy where
f= 4mM (m+M)
10marks 5 marks
(c) A fast neutron enters a target of carbon nuclei which may be assumed to have masses 12 times that of the neutron. How many head-on collisions will it take
before the neutron loses 95% of its energy?
4 marks
(d) Suggest one reason why in a real reactor a neutron is likely to make more
collisions with the moderator nuclei before losing this much energy
2
1 mark
Answer:
Part A
a) F = -16x + 4, b) x = 0.25 m, c) STABLE
Explanation:
Part A
a) Potential energy and force are related
F = [tex]- \frac{dU}{dx}[/tex]- dU / dx
F = - (8 2x -4)
F = -16x + 4
b) The object is in equilibrium when the forces are zero
0 = -16x + 4
x = 4/16
x = 0.25 m
c) An equilibrium position is called stable if with a small change in position, the forces make it return to the initial position, in case the forces make it move away it is called unstable.
In this case there is only one equilibrium point
by changing the position a bit
x ’= x + Δx
we substitute
F ’= - 16 x’ + 4
F ’= - 16 (x + Δx) + 4
F ’= (-16x +4) - 16 Δx
at equilibrium position F = 0
F ’= 0 - 16 Δx
we can see that the body returns to the equilibrium position, therefore it is STABLE
PART B
This is an exercise in body collisions, let's define the system formed by the two bodies in such a way that the forces during the collisions are internal and the moment is conserved
initial instant. Before the shock
p₀ = m v
final instant. After the crash
p_f = (m + M) v_f
We have two possibilities: an elastic collision in which the bodies separate, each one maintaining its plus, and an INELASTIC collision where the neutron is absorbed by the nucleus and the final mass is M '= m + M, in this case they indicate that the collision is elastic
p₀ = pf
mv = mv ’+ M v_f
in the case of the elastic collision, the kinetic energy is conserved
K₀ = K_f
½ m v² = ½ m v’² + ½ M v_f²
we write the system of equations
mv = mv ’+ M v_f (1)
m (v² -v'²) = M v_f ²
m (v - v ’) = M v_f
m (v-v ’) (v + v’) = M v_f
v + v ’= v_f
we substitute in equation 1 and solve
v ’=[tex]\frac{m -M }{m+M } \ vo[/tex]
v_f = [tex]\frac{2m}{m+M} \ v_o[/tex]
the mechanical energy of the neutron is
initial
Em₀ = K = ½ m v²
final moment
Em_f = K + U = ½ m v_f ² + U
U is the energy lost in the collision
total energy is conserved
Em₀ = Em_f
½ m v² = ½ m v_f ² + U
U = ½ m (v² -v_f ²)
U = ½ m [v² - ( [tex]\frac{m-M}{m+M}[/tex] v)² ]
U = ½ m v² [1- ( [tex]\frac{m-M}{m+M}[/tex] )² ]
U = ½ m v2 [ [tex]\frac{2M}{m+M}[/tex]]
U = [tex]\frac{2 mM}{m +M } \ v^2[/tex]
Let's do the same calculations for the nucleus
initial Em₀ = 0
final Em_f = K + U = ½ M v_f ² + U
Em₀ = Em_f
0 = K + U
U = -K
U = - ½ M v_f ²
U = - ½ M [ [tex]\frac{2m}{m+M} \ v[/tex] ]²
U = [tex]\frac{2 m M }{m+M} \ v^2[/tex]
We can see that we obtain the same result, that is, the potential energy lost by the neutron is equal to the potential energy gained by the nucleus.
b) the fraction of energy lost
f = U / Em₀
f = 4 m M / m + M
c) let's calculate the fraction of energy lost in a collision
m = 1.67 10⁻²⁷ kg
M = 12 1.67 10⁻²⁷= 20 10⁻²⁷ kg
f = 4 1.6 20 / (1.6+ 20) 10⁻²⁷
f = 5.92 10⁻²⁷ J
the energy of a fast neutron is greater than 1 eV
Eo = 1 eV (1.67 10⁻¹⁹ J / 1eV) = 1.67 10⁻¹⁹ J
Let's use a direct portion rule if in a collision f loses in how many collisions it loses 0.95Eo
#_collisions = 0.95 Eo / f
#_collisions = 0.95 1.67 10⁻¹⁹ / 5.92 10⁻²⁷
#_collisions = 2.7 10⁷ collisions
A car took 5 minutes to travel from town A to town B which are 12km apart.Calculate the average speed of the path.
Speed = distance / time
Speed = 12km / 5 minutes
Speed = 2.4 km per minute
Speed is measured per hour, 1 hour has 60 minutes.
2.4 km per minute x 60 minutes = 144 km per hour
Which statement or question is a good hypothesis
person has a mass of 60kg. How much do they weigh on Earth, if the gravitational field strength is 10 N/kg?
Answer:
588n is the answer may be
A stream leaving a mountain range deposits a large part of its load in a __
Answer:
(n) alluvial fan sandbar
Explanation:
It takes 130 j of work to compress a certain spring 0.10m. (a) what is the force constant of this spring? To compress the spring an additional 0.10m, does it take 130
Answer:
Explanation:
The PE equation for a mass/spring system is
[tex]PE=\frac{1}{2}k[/tex]Δx² and filling in:
[tex]130=\frac{1}{2}k(.10)^2[/tex] and
[tex]k=\frac{2(130)}{(.10)^2}[/tex] so
k = 26000 N/m
If the displacement from equilibrium changes more, the PE needed to compress it will also change.
[tex]PE=\frac{1}{2}(26000)(.20)^2[/tex] gives us that
PE = 520J
In a second order lever system the force ratio is 2.5, the load is at the distance of 0.5m from the fulcrum find distance of effort if it losses are negligible
Answer:
1.25 m
Explanation:
From the question given above, the following data were obtained:
Force ratio = 2.5
Distance of load from the fulcrum = 0.5 m
Distance of effort =.?
The distance of the effort from the fulcrum can be obtained as illustrated below:
Force ratio = Distance of effort / Distance of load
2.5 = Distance of effort / 0.5
Cross multiply
Distance of effort = 2.5 × 0.5
Distance of effort = 1.25 m
Therefore, the distance of the effort from the fulcrum is 1.25 m
. A car accelerates uniformly from 0 to 72 km/h in 11.5 seconds.
a) What is the acceleration of the car in m/s2? b) What is the position of the car by the time it reaches the velocity of 72 km/h?
Answer:
Explanation:
First job is to convert 72 km/hr to m/s:
[tex]72\frac{km}{hr}[/tex] × [tex]\frac{1000m}{1km}[/tex] × [tex]\frac{1hr}{3600s}[/tex] = 2.0 × 10¹ m/s
Now to find the acceleration which is
[tex]a=\frac{v_f-v_0}{t}[/tex] and filling in:
[tex]a=\frac{2.0*10^1-0}{11.5}=1.7\frac{m}{s^2}[/tex] That's part a. Part b want to know how far the car can get in 11.5 seconds (because that's the time it takes for the car to get to 72 km/hr). Since we know that the car can get 2.0 × 10¹ meters in 1 second, that means that in 11.5 seconds, the car can get 11.5(2.0 × 10¹) which is 230 meters.
a sprinter runs 100m in12.5seconds calculate the speed
Answer:
8m in 1 second
480m = 1 hour
11,520m in one day
Explanation:
Hope this is helpful
a stone of mass 250kg and another stone of mass 400 kg are kept at a distance of 100m what amount of gravitational force develops between them?
Explanation:
Hey there!
Given;
Mass of one object (m1) = 250kg
Mass of another object (m2) = 400 kg
Distance (d) = 100 m
Gravitational constant (g) = 6.67*10^-11
Now;
[tex]f = \frac{g.m1.m2}{ {d}^{2} } [/tex]
Keep all values;
[tex]f = \frac{6.67 \times {10}^{ - 11} \times 250 \times 400}{ {(100)}^{2} } [/tex]
Simplify
[tex]f = \frac{6.67 \times {10}^{ - 11} {10}^{5} }{10000} [/tex]
[tex]f = \frac{6.67 \times {10}^{ - 6} }{10000} [/tex]
Therefore, gravitational force is 6.67*10^-10.
Hope it helps!
While using a digital radiography system, suppose a radiographer uses exposure factors of 10 mAs and 70 kVp with an 8:1 grid for an AP shoulder radiograph with acceptable anatomical part penetration and detector element (DEL) exposure. If the radiographer desires to increase scatter absorption using a 12:1 grid, what new exposure factors should be used to maintain the same DEL exposure
Answer:
b. 12.5 mAs, 70 kVp
Explanation:
The given parameter are;
The initial exposure factors := 10 mAs and 70 kVp
The initial Grid Ratio, G.R.₁ = 8:1
The Grid Ratio with which the radiographer desires to increase the scatter absorption, G.R.₂ = 12:1
Given that the lead content in the 12:1 grid, is higher than the lead content in 8:1 grid and that 12:1 grid needs more mAs to compensate, and provides a higher image contrast, the amount of extra mAs is given by the Grid Conversion Factors, GCF, as follows;
The GCF for G.R. 8:1 = 4
The GCF for G.R. 12:1 = 5
Therefore, given that the mAs used by the radiographer for 8:1 Grid Ratio is 10 mAs, the mAs required for a G.R. of 12:1 in order to maintain the same exposure is given as follows;
mAs for G.R. of 12:1 = 10 mAs × 5/4 = 12.5 mAs
Therefore the new exposure factors are;
12.5 mAs, 70 kVp
convert the following as instructed
67 kg into gram
explain step by step
please reply quickly its urgent
Answer:
1kg = 1000g
67kg therefore would be equal to
67 x 1000 = 67,000g = 6.7 x 10⁴g.
Two parallel conducting plates are separated by 12.0 cm, and one of them is taken to be at zero volts. (a) What is the magnitude of the electric field strength between them, if the potential 5.6 cm from the zero volt plate is 450 V
Answer:
-8.036 kV/m
Explanation:
The electric field E = -ΔV/Δx where ΔV = change in electric potential = V - V' where V = electric potential at x = 5.6 cm = 450 V and V' = electric potential at x = 0 cm, = 0 V . So, ΔV = V - V' = 450 V - 0 V = 450 V.
Δx = distance between the 0 V plate and the 450 V point = 5.6 cm = 0.056 m
So, E = -ΔV/Δx
Substituting the values of the variables into the equation, we have
E = -ΔV/Δx
E = -450 V/0.056 m
E = -8035.7 V/m
E = -8.0357 kV/m
E ≅ -8.036 kV/m
Since the electric field between two parallel conducting plates is constant, the electric field between the plates is E = -8.036 kV/m
prove that vector addition obeys commutative and associative laws
the order of vector addition doesn't affect the resultant vector and grouping or order of pair doesn't effect the sum.
Name One formula that uses joules
Answer:
[tex]{ \bf{power \: { \tt{(watts)}} = \frac{workdone \: { \tt{(joules)}}}{time \: { \tt{(seconds)}}} \: }}[/tex]
difine scalar quantity
Scalar quantity are physical quantities that have just magnitude, not direction.
It is always positive.Examples: Speed, distancea stone is projected horizontally with 20 m/a from top of a tall building. calculate it's position and velocity after 3s neglecting the air resistance
Answer:
1. 45 m
2. 50 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 20 m/s
Time (t) = 3 s
1. Determination of the position (i.e height)
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
h = ½gt²
h = ½ × 10 × 3²
h = 5 × 9
h = 45 m
2. Determination of the velocity.
Initial velocity (u) = 20 m/s
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Velocity (v) =?
v = u + gt
v = 20 + (10 × 3)
v = 20 + 30
v = 50 m/s
Apakah yang berlaku kepada kekuatan medan magnet jika satu lagi sel kering 1.5 v ditambahkan
Answer:
The magnetic field is doubled.
Explanation:
What happens to the strength of the magnetic field if one more 1.5 v dry cell is added?
The magnetic field due to a current carrying conductor is directly proportional to the current flowing in the wire.
If we connect one more battery of 1.5 V so the voltage is doubled and according to the Ohm's law, as the resistance of wire is constant, so the current in the wire is also doubled.
When the current doubles, the magnetic field produced by the wire is also doubled.
