HELP PLSSS I HAVE AN EXAM MONDAY AND I THINK THIS IS GONNA BE ON ITTTT
A fish is at the western bank of a river that is 64 m wide and has a current with a velocity of 0.90 m/s [S]. The fish swims directly across the river going due east. The fish can swim at a speed of 0.2 m/s.
a) How long does it take for the fish to get across the river
b) What is the resulting velocity of the fish
c) When the fish arrives on the opposite bank, how far is it from being at the point directly across from where it started?
The answers are here, please show work on how to get these
a) 3.2 x 10^2
b) 0.9 m/s (S 13 E)
c) 2.9 x 10^2
(a) 3.2 x 10²s
(b) 0.9 m/s (S 13 E)
(c) 2.9 x 10²m
Explanation:The sketch illustrating the scenario has been attached to this response.
As shown;
The fish swims due east with a velocity [tex]V_{x}[/tex] = 0.2m/s
The river current has a velocity [tex]V_{y}[/tex] due South = 0.9m/s
The resultant of the velocity is V
The width of the river is x = 64m
(a) To calculate how long it took the fish to get across the river, we know that velocity is the rate of change in distance, therefore we can use the relation;
V = [tex]\frac{d}{t}[/tex] -------------(i)
Where;
V = velocity of the fish = [tex]V_{x}[/tex] = 0.2m/s
d = distance from the start to the end = width of the river = x = 64m
t = time taken to move for that distance
Make t subject of the formula in equation (i);
t = [tex]\frac{d}{V}[/tex]
Substitute the values of d and V into the equation;
t = [tex]\frac{64m}{0.2m/s}[/tex]
t = 320 s
t = 3.20 x 10²s
Therefore, the time taken for the fish to get across the river is 3.20 x 10²s
(b) The resulting vector of the fish is V whose magnitude is the algebraic sum of vectors [tex]V_{x}[/tex] and [tex]V_{y}[/tex], and direction is given by θ. i.e
The magnitude of the resulting vector is;
|V| = [tex]\sqrt{(V_x)^2 + (V_y)^2}[/tex]
|V| = [tex]\sqrt{(0.2)^2 + (0.9)^2}[/tex]
|V| = [tex]\sqrt{(0.04) + (0.81)}[/tex]
|V| = [tex]\sqrt{(0.85)}[/tex]
|V| = 0.92m/s
|V| ≅ 0.9m/s
The direction of the resulting vector θ and is given by;
tan θ = [tex]\frac{V_y}{V_x}[/tex]
tan θ = [tex]\frac{0.9}{0.2}[/tex]
tan θ = 4.5
θ = tan⁻¹ ( 4.5)
θ = 77.47° South of East.
θ ≈ 77.5° South of East.
Subtracting θ = 77.5° from 90° gives its value East of South
i.e
90 - 77.5 = 12.5° East of South
This can also be written as S12.5°E
Approximating to the nearest whole number gives S 13 E
Therefore, the resulting velocity of the fish is 0.9m/s in the direction S13°E
(c) When the fish arrives on the opposite bank, its distance from being at the point directly across from where it started is the product of the velocity of the river current and the time taken by the fish to get across the river. This point is equivalent to k as shown in the diagram.
Therefore;
distance = velocity of river current x time taken
distance = 0.9m/s x 3.20 x 10²s
distance = 2.88 x 10²m
distance ≅ 2.9 x 10²m
Notice that the velocity of the river current is used since that's the velocity of the fish on the y-axis.
The temperature of an ideal gas in a sealed 0.40m3 rigid container is reduced from 350 K to 270 K.The final pressure of the gas is 60 kPa. The molar heat capacity at constant volume of the gas is 28.0 J/(mol K). The heat absorbed by the gas is closest to
Answer:
The answer is below
Explanation:
Given that the volume (V) = 0.4 m³, temperature difference (ΔT) = 270 K - 350 K = -80 K, pressure (P) = 60 kPa = 60000 Pa, R = 8.314 J/molK
Since we have constant volume, we can use the final state parameters to calculate the number of moles using the ideal gas law:
[tex]PV=nRT\\\\n=\frac{PV}{RT} =\frac{60000*0.4}{8.314*270} =10.69\ moles[/tex]
Given that the molar heat capacity at constant volume ([tex]C_v[/tex]) = 28.0 J/(mol K), the heat absorbed (Q) is:
[tex]Q=nC_v\Delta T=10.69*28*(-80) = -23945.6\ J\\\\Q=-23.95\ kJ[/tex]
Q ≈ -24 kJ
A 45000 watt crane operating at full power lifts a 2100 kg object vertically for 17.4 seconds. How high has the crane lifted the object?
Answer:
Explanation:
We need the power equation here, which is:
Power = (F * Δx)/time
where F * Δx is the amount of work done.
F is a force which is measured in Newtons. We are given the mass of the object, but since we need a Force measure, we need the weight of the object:
F = 2100(9.0)
F = 21000 to the correct number of sig dig.
Now we can plug in the values we have and solve for the displacement, Δx:
[tex]45000=\frac{21000x}{17.4}[/tex] and isolating x:
[tex]\frac{17.4(45000)}{21000}=x[/tex] so
x = 37 m
2. CaCl2 (s) + 2H20 ---> Ca(OH)2 (aq) + 2HCl (g) + heat
Is it an endothermic reaction?
Answer:
no
Explanation:
Calcium chloride is a chemical compound made up of calcium ions and chlorine ions. ... Mixing calcium chloride with water is an exothermic reaction, which means that the combination of the two substances releases heat. Thus, when you add calcium chloride to water, the solution heats.
Can anybody answer ??
Answer:
C. Electromagnetic wave
Explanation:
Please give me brainliest
Answer:
C. electromagnetic
Explanation:
because 5g uses higher frequency radio waves a type of electromagnetic radiation which are within the spectrum considered safe.
Which state has the most fixed shape?
O A. Gas
O B. Solid
O C. Liquid
O D. Plasma
Answer: Liquid
“A substance will take on the shape of an open container if it is a Liquid. Explanation: The major state of matter are solid, liquid and gas. Liquid usually have a definite volume.”
Answer:
solid
Explanation:
Solids are fixed and solid.
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)
Convert 162 km/h into m/s.
Answer:
45 m/s
Explanation:
162 / 3.6 = 45 m/s
Divide by 3.6 to convert km/h to m/s.
electromotive force in a circuit;
A) causes free electrons to flow
B) increases the circuit resistance
C) maintains circuit resistance
D) it needed to make the circuit complete
Answer:
A causes free electrons to flow
Explanation:
The amount of force that causes electrons to flow in a conductor is called electromotive force.
Which of these events is an example of resonance?
A- a bridge collapses due to the overloading of vehicles using it.
B-A baker kneads dough by pounding it repeatedly
C-The sound of teo guitars changes from loud to soft every second
D- An ambulance siren rises and falls in frequency as it passes by you
E-An opera singer breaks a thin glass with only the use of her high frequency voice
Answer: E- An opera singer breaks a thin glass with only the use of her high frequency voice
Explanation:
Resonance is when a person is able to evoke emotions or when a person is deep in character. It is the ability to evoke memories, images and emotions.
Examples of resonance include old pictures which has emotional attachments, feel voice of a singer etc.
Therefore, the event that is an example of resonance is an opera singer breaks a thin glass with only the use of her high frequency voice.
what are the horizontal and vertical components of a vector that is 25units long with an angle of 130 degrees
Answer:
The horizontal component of the vector is approximately -16.07
The vertical component of the vector is approximately 19.15
Explanation:
A vector quantity is a quantity that posses both magnitude and direction specifications
The magnitude of the given vector, R = 25 units
The direction of the vector, θ = 130°
Therefore the location of the vector, starting from the origin of the Cartesian plane, is in the second quadrant having an angle of 180° - 130° = 50° to the horizontal
Given that the x-coordinate is negative in the second quadrant, we have;
The horizontal component of the vector, Rₓ = The x-coordinate of the vector = R×cos(θ)
∴ The horizontal component of the vector, Rₓ = 25 × cos(130°) = -25 × cos(50°) ≈ -16.07
The horizontal component of the vector, Rₓ ≈ -16.07
The vertical component of the vector, [tex]R_y[/tex] = The y-coordinate of the vector = R×sin(θ)
∴ The vertical component of the vector, [tex]R_y[/tex] = 25 × sin(130°) ≈ 19.15
The vertical component of the vector, [tex]R_y[/tex] ≈ 19.15
The vector can be resolved as R = -16.07·i + 19.15·j
A trip is taken that passes through the following points in order
Point A Om
Point B 15.0 m
Point C -30.0 m
Point D 20.0 m
Point E -10.0 m
Point F 5.0 m
What is the displacement from Point B to Point E?
A) 5.0 m right
B) 85 m right
C) 25.0 m left
D) 85 m left
Answer:
The displacement from point B to point E is 25.0 m left
Select the correct answer
If the resistance in a circuit remains constant, what happens to the electric power when the current increases?
OA. The power will increase.
OB.
The power will decrease,
OC. There will be no power.
OD
The current does not affect the power,
Reset
Next
[tex]\large\mathrm{A. Power\:\: will \:\:Increase }[/tex]
Explanation :We know that,
[tex]\large \mathrm{ \boxed{P = I²R}}[/tex]
where,
P = electric powerR = resistanceI = electric currentAnd when resistance is constant, the power of the circuit will change proportionally with the change in electric current. therefore, if current increases then the electric power of the circuit will increase too.
[tex]\large\mathfrak{{\pmb{\underline{\orange{hope \: \: i t \: \: helps \: \: you}}{\orange{.....}}}}}[/tex]
According to Archimedes' principle, when will an object float in water?
A. When its volume is less than the volume of water it displaces
B. When its weight is equal to the buoyant force exerted by the water
C. When its density is greater than the density of water
D. When its weight is greater than the weight of water it displaces
Answer:
Its B
Explanation:
a p e x
what is the pressure exerted, what is the pressure exerted by 50kg girl as she places her weight on one shoe if the heels area is 0.002m²
Answer:
The pressure exerted by the girl is 245,000 N/m²
Explanation:
Given;
mass of the girl, m = 50 kg
area of the girl's shoe, A = 0.002 m²
The pressure exerted by the girl is calculated as follows;
[tex]P = \frac{F}{A} \\\\Where;\\F \ is \ the \ force \ exerted \ by \ girl's \ weight\\\\P = \frac{F}{A} = \frac{mg}{A} = \frac{50 \times 9.8}{0.002} = 245,000 \ N/m^2[/tex]
Therefore, the pressure exerted by the girl is 245,000 N/m²
The two waves shown here are the same distance from point X and are traveling toward each other.
An illustration with a crest 2.0 centimeters high traveling to the right and a second 2.0 centimeters trough traveling toward the left toward point X in the material.
What is the amplitude of the resulting wave when the two waves meet at point X?
0.0 cm
1.0 cm
2.0 cm
4.0 cm
Answer:
(C) on edge.
Explanation:
Answer:
2.0
Explanation:
trust the process.
As an IT technician for your company, you have been notified that the Windows domain does not seem to be functioning properly. Being familiar with domains, you are fairly confident you know what the issue is. But just to be safe, you take the applicable time to gather additional information and to identify what, if anything, has changed.
Which of the following is the BEST next step?
A. Determine the appropriate fix.
B. Create a hypothesis.
C. Implement the fix.
D. Identify what has changed.
E. Gather information.
Answer: Create a hypothesis
Explanation:
From the information given, information has been gathered and the identification to ascertain if there's a change. Then, an hypothesis has to be created in order to know what the problem is.
One has to carry out some research in order to know what went wrong and should also validate the hypothesis by consulting with ones peers. By doing this, the most likely causes of the issues will be gotten.
can someone please help
Answer: D
Explanation: because doing a yoga desk program is physical activity, 10k steps is pysical activity, riding a bike or walking/running is also physical activity. so it should be D, all of the above.
In a wire, when elongation is 4 cm energy stored is E. if it is stretched by 4 cm, then what amount of elastic potential energy will be stored in it?
4E
Explanation:The elastic potential energy of an elastic material (e.g a spring, a wire), is the energy stored when the material is stretched or compressed. It is given by
U = [tex]\frac{1}{2}kx^2[/tex] --------------------(i)
Where;
U = potential energy stored
k = spring constant of the material
x = elongation (extension or compression of the material).
From the first statement;
when elongation (x) is 4cm, energy stored (U) is E
Substitute these values into equation (i) as follows;
E = [tex]\frac{1}{2}k(4)^2[/tex]
E = 8k
Make k subject of the formula
k = [tex]\frac{E}{8}[/tex] [measured in J/cm]
From the second statement;
It is stretched by 4cm.
This means that total elongation will be 4cm + 4cm = 8cm.
The potential energy stored will be found by substituting the value of x = 8cm and k = [tex]\frac{E}{8}[/tex] into equation (i) as follows;
U = [tex]\frac{1}{2}\frac{E}{8} (8)^2[/tex]
U = [tex]\frac{1}{2}{8E}[/tex]
U = [tex]{4E}[/tex]
Therefore, the potential energy stored will now be 4 times the original one.
You plan to use a slingshot to launch a ball that has a mass of 0.019 kg. You want the ball to accelerate straight toward your target at 23 m/s2. How much force do you need to apply to the ball?
Answer:
Explanation:
this is a simple application of Newton's 2nd Law: F = ma.
F = .019(23) so
F = .44 N
You would need to apply a force of 0.437 Newtons to the ball in order to achieve the desired acceleration of 23 m/s².
Force is a physical quantity that describes the interaction between objects or systems and their ability to change motion or shape. It is a vector quantity, meaning it has both magnitude and direction. Force can cause an object to accelerate, decelerate, or change direction.
According to Newton's second law of motion, force is directly proportional to the mass of an object and the acceleration it experiences. The equation F = m × a represents this relationship, where F is the force, m is the mass of the object, and a is the acceleration.
Force can be measured in various units, such as Newtons (N) in the International System of Units (SI) or pounds (lb) in the US customary system. Common examples of forces include gravity, friction, tension, compression, and applied forces like pushing or pulling an object.
According to Newton's second law of motion, which states that force (F) is equal to mass (m) multiplied by acceleration (a):
F = m × a
In this case, the mass of the ball is given as 0.019 kg, and the desired acceleration is 23 m/s². Plugging these values into the equation, we can calculate the force:
F = 0.019 kg × 23 m/s²
F = 0.437 kg m/s²
Learn more about Force, here:
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I am confused and need help with the question above??
If the light ray hits the first mirror and continues to bounce off the other mirrors inside the box, determine where the light ray will eventually hit on the border
Answer: Light ray X will eventually hit the borader
Explanation:
A man can jump 2 m on the surface of the earth, calculate the height that he can jump on the surface of the moon?
Answer:
hi
Explanation:
it is probably 12 m on the surface of the moon
have a good day
I hope this is help full to you
Please help me :))
Which golf ball would hit the surface with the greatest impact: a ball that fell one meter above the surface of the Earth or a ball that fell one meter above the surface of the Moon?
Answer:
the one above the surface of earth
Explanation:
earth has gravity the ball of the moon would float away
Using a 100 year time frame,what is the CO2e of 1 tonne of CO2,2 tonne or methane,and 3 tonnes of nitrous oxide
Well, let's see what we've got here:
( 4⁻³ · 3⁴ · 4² ) / ( 3⁵ · 4⁻² ) .
The two simple rules of exponents that we're
going to use here are:
-- Two multiply two numbers with the same base,
add their exponents. Like (A³) · (A²) = A⁵ .
But the bases have to be the same.
-- A negative power just means it belongs in the
other section of a fraction.
A negative power on top means it belongs on the bottom.
A negative power on the bottom means it belongs on top.
Like A⁻² means 1/A² . And 1/B⁻³ means B³ .
That's all you need in order to clean up the big fraction
in the question. But in order to see where you can use
these rules, you need to re-arrange things first.
Original: ( 4⁻³ · 3⁴ · 4² ) / ( 3⁵ · 4⁻² )
Let's send the 4⁻³
to the bottom
where it belongs: ( -- 3⁴ · 4² ) / 4³ · ( 3⁵ · 4⁻² )
Not take that 4⁻² from
the bottom, and put it on
top, where it belongs: ( 4² · 3⁴ · 4² ) / 4³ · ( 3⁵ -- )
Multiply the 4²s on top: ( 4⁴ · 3⁴ ) / ( 4³ · 3⁵ )
Now let me break this up.
Not changing anything, just
writing it in a different way: ( 4⁴ / 4³ ) · ( 3⁴ / 3⁵ )
Look at the first fraction: 4⁴ / 4³ .
Divide top and bottom by 4³ , and it becomes just 4 .
Now look at the second fraction: 3⁴ / 3⁵ .
Divide top and bottom by 3⁴ , and it becomes just 1/3 .
So in the end, we're left with just 4 / 3 .
And THAT is exactly equal to the original big messy fraction
in the question. It has exactly the same numerical value, but
you'd never know it when you see it, because it's a lot simpler.
There are a lot of other ways we could have manipulated and
massaged the original fraction, but the steps are the same:
-- Multiply numbers with the same base, by adding the exponents.
-- Remember that a number with a negative exponent belongs
in the other section of the fraction, with a positive exponent.
Đặt vào đầu hai dây dẫn cùng một hiệu điện thế bằng nhau U,có điện trở lần lượt là R1 và R2.Ta thấy cường độ dòng điện qua dây dẫn thứ nhất I1 lớn gấp hai lần cường độ dòng điện qua dây dẫn thứ hai I2
Answer:
The resistance ratio of first conductor to the second conductor is 1 : 2.
Explanation:
Current in first conductor = I1
Current in second conductor = I2 , I1 = 2 I2
According to the Ohm's law
[tex]V= I_1R_1..... (1)\\V = I_2 R_2 .... (2)\\[/tex]
From (1) and (2)
[tex]I_1 R_1 = I_2 R_2\\\\2I_2 R_1 = I_2 R_2\\\\2 R_1 = R_2[/tex]
Convergent boundaries are responsible for
Answer:
A
Explanation:
The plate collisions that occur in these areas can produce earthquakes, volcanic activity, and crustal deformation.
hope it helps you
A 750 kg car moving at 25 m/s has Kinetic Energy. To stop the car requires work. On snowy roads, the force of friction that can
stop a car reduces to only about 725 N.
a. How much work must be done to stop the car? (Hint: What is the car's kinetic energy?)
b. How far will the car travel before stopping if the only force stopping it is friction between the tires and the road?
a. By the work-energy theorem, the total work required to stop the car is equal to the change in its kinetic energy,
W = 0 - 1/2 (750 kg) (25 m/s)² ≈ -230 kJ
b. The car covers a distance x as it stops such that
W = (-725 N) x ==> x ≈ 320 m
When the surface of a metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased (so the light is just brighter), what value will also increase?
A. the maximum kinetic energy of the ejected electrons
B. the number of electrons ejected per second
C. the time lag between the onset of the absorption of light and the ejection of electrons
please help!!!
So, we know that this question is about photoelectric effect.
What is photoelectric effect?
-Photoelectric effect is a phenomenon where electrons are released from a material whenever an electromagnetic radiation such as light, hits it.
-This phenomenon is first discovered by Heinrich Rudolf Hertz in 1887 whereas Albert Einstein, in 1905, resolved the conflict between the photoelectric effect and Maxwell's electromagnetic wave theory of light.
Now to your question, the intensity of light only determines the number of the electrons released, not their maximum kinetic energy because this are proportional to the light's frequency.
Also, there is no time lag detected between the entry of radiation and the emission of electrons in experiments held.
So, with letter A and C out, we can therefore conclude that the answer for this is Letter B
The correct answer is B: the number of electrons ejected per second
The Einstein photoelectric equation states that;
[tex]KE = hf - hfo[/tex]
Where
KE = kinetic energy of the ejected photo electrons
h = Plank's constant
f = frequency of incident light
fo = threshold frequency.
The kinetic energy of ejected photoelectrons depends on frequency of incident photon and not on the intensity of the incident photon.
However, the number of photoelectrons ejected per second depends on the intensity of the incident blue light.
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which of the following is incorrect for nuclear forces
a) they are attractive in nature
b) they are short range forces
c) they obey inverse square law
d) they are non conservative in nature
Answer:
c they obey inverse square law
