Answer:
It's C. Moving Waterrrr
A 1.00-m3 object floats in water with 30.0% of its volume above the waterline. What does the object weigh out of the water?
Answer:
Object's weight = 6,839.42 N
Explanation:
Given
Above waterline = 30%
Volume of object = 1m^3
Required
Determine the weight of the object
First, we need to calculate its Mass
Mass = Density of Water * Volume of object in water
Density of water = 997kg/m³
If 30% is above waterline, then 70% is in water.
So:
Mass = Density of Water * Volume of object in water
Mass = 997kg/m³ * 70%m³
Mass = 997kg * 70%
Mass = 697.9 kg
The object weight sis then calculated as thus:
Weight = Mass * Acceleration of gravity
Weight = 697.9 kg * 9.8m/s²
Weight = 6 839.42 N
I need help understanding this question, so I know the arrow is traveling 80 meters per second, but it was launched from a starting point of 32 meters. I know for a fact an arrow does not have any thrust left at around 3 seconds of being in the air.
I just need someone to explain the questions and provide an answer to each.
Answer:
a) h(g) = 358,53 m
b) t = 8,16 s
c) t(t) = 16,71 s
Explanation:
Equations for vertical shooting are:
Vf = V₀ - g * t ; h = V₀*t - (1/2)*g*t² ; Vf² = V₀² - 2*g*h
And at maximum heigt Vf = 0 then
0 = V₀ - g * t
t = V₀/g V₀ = 80 m/s and g = 9,8 m/s²
t = 80 / 9,8 (s)
t = 8,16 s
Then 8,16 s is the time to get maximum height
If we plug t = 8,16 (s) in equation h = V₀*t - (1/2)*g*t²
we get: h (max) = (80)*8,16 - 0,5*9,8*(8,16)² (m)
h (max) = 652,8 - 326,27 m
h (max) = 326,53 m
Then relative to ground that height becomes
h(g) = 326,53 + 32
h(g) = 358,53 m
In order to get the time the arrow is in the air we proceed as follows:
a) for the arrow to be at the launched point will take the same time that from the launched point to the maximum height, and after that we have to find out the time the arrow takes from 32 m down to the ground level
Then
t(t) = 8,16 + 8,16 + tₓ (2)
Where tₓ is the time from 32 m height to ground
h = V₀*tₓ - (1/2)*g*tₓ² but since the arrow now is going down then we change the sign of the second term on the right side of the equation
32 = (80)*tₓ + 0,5 * 9,8 * tₓ² Note that when the arrow is at 32 m height the speed is again V₀ = 80 m/s
32 = 80*tₓ + 4,9*tₓ²
A second-degree equation for tₓ, solving it
4,9*tₓ² + 80*tₓ - 32 = 0
t₁,₂ = -80 ± √ 6400 + 627,2 / 9,8
t₁,₂ =( - 80 ± 83,8 ) / 9,8
there is not a negative time therefore we dismiss such solution and
t₁ = 3,8 / 9,8
t₁ = 0,39 s
And
t(t) = 8,16 + 8,16 + 0,39 s
t(t) = 16,71 s
If an ocean wave passes a stationary pointevery 4 s and has a velocity of 7 m/s, what isthe wavelength of the wave?Answer in units of m.
Answer:
28mExplanation:
Step one:
given data
period T= 4seconds
velocity v= 7m/s
wave lenght λ=?
Step two:
we know that f=1/T
the expression relating period and wave lenght is
v=λ/T
λ=v*T
λ=7*4
λ=28m
The wavelength of the wave is 28m
helppp please ?????????
Answer:
v=59[m/s]
Explanation:
To solve this problem we must use the principle of conservation of energy, which tells us that energy is transformed from Kinetic to potential or vice versa. At the moment when the car is at the top before falling down the cliff, we have the car moving at speed 50 [m/s] (kinetic energy) also it is 50 [m] above ground level (potential energy).
[tex]E_{k1}+E_{p1}=E_{k2}\\[/tex]
where:
Ek1 = kinetic energy before falling [J]
Ep1 = potential energy before falling [J]
Ek2 = kinetic energy in the ground [J]
The potential energy can be calculated by means of the following equation.
[tex]E_{p}=m*g*h[/tex]
where:
m = mass = 500 [kg]
g = gravity acceleration = 9.81 [m/s²]
h = elevation = 50 [m]
Whereas the kinetic energy can be calculated by means of the following equation.
[tex]E_{k}=\frac{1}{2}*m*v^{2}[/tex]
where:
v = velocity = 50 [m/s]
Now replacing in the general equation:
[tex]\frac{1}{2} *500*(50)^{2} +500*9.81*50=\frac{1}{2} *500*v^{2}\\625000+245250=250*v^{2} \\250*v^{2} =870250\\v=\sqrt{870250/250} \\v=59[m/s][/tex]
Objects accelerate because
What is the initial vertical velocity of the ball?
A.
0 m/s
B.
9.81 m/s
C.
20.0 m/s
D.
60.0 m/s
A statement of the second law of thermodynamics is that:__________.
a) spontaneous reactions are always exothermic.
b) energy is conserved in a chemical reaction that has a decrease in entropy.
c) spontaneous reactions are always endothermic.
d) in a spontaneous process, the entropy of the universe increases.
Answer:
in a spontaneous process, the entropy of the universe increases.
Explanation:
Entropy is a measure of of the degree of randomness or disorderliness in a system.
The second law of thermodynamics can be stated as follows; "in any spontaneous process, the entropy of the universe increases."
The universe here refers to the system's disorder and the disorder of the surroundings. Therefore, a spontaneous process can occur, in which the entropy of the system decreases, only if the entropy increases in the surroundings.
For instance, when ice freezes, the entropy of liquid water decreases, that is, the entropy of the system decreases. However, heat is given off to the surroundings and the entropy of the surroundings increases. This is an obvious expression of this law.
Calculate the RMS speed of helium atoms near the surface of the Sun at a temperature of about 5300 K.
Answer:
RMS velocity, [tex]v_{rms}=5748.75\ m/s[/tex]
Explanation:
We need to find the RMS speed of helium atoms near the surface of the Sun at a temperature of about 5300 K.
The formula for RMS speed of a gas is given by :
[tex]v_{rms}=\sqrt{\dfrac{3RT}{m}}[/tex]
Where
R is ideal gas constant, R = 8.314 J /mol K
T = 5300 K
m is molar mass of Helium, [tex]m = 4\times 10^{-3}\ Kg/mol[/tex]
Substituting all the values in above formula :
[tex]v_{rms}=\sqrt{\dfrac{3\times 8.314\times 5300}{4\times 10^{-3}}}\\\\=5748.75\ m/s[/tex]
So, the RMS speed Helium atoms 5748.75 m/s.
What do light and energy tell us about the universe?
need a paragraph
A 200-N object floats with three-fourths of its volume beneath the surface of the water. What is the buoyant force on the object?
Answer:
Buoyant Force = 200N
Explanation:
Given
[tex]Object = 200N[/tex]
Required
Determine the buoyant force?
Using Archimedes principle:
When an object is immersed in a fluid, the object is acted upon on by an upward force (Buoyant force) which equals the weight of the object.
In other words;
Buoyant Force = Weight of object
Hence:
Buoyant Force = 200N
The buoyant force on the object which floats with three-fourths of its volume beneath the surface of the water is 200 N.
What is the buoyant force?The buoyant force is the force which is applied by the fluid in the upward direction when a object is placed over it. This buoyant force can be calculated with the following formula.
[tex]F_b=-\rho gV[/tex]
Here, (ρ) is the density of the fluid, (g) is the gravitation force and (V) is the fluid volume.
The buoyant force is equal to the weight of the liquid displace by the object which is placed on it.
It is given that the 200-N object floats with three-fourths of its volume beneath the surface of the water.
This force applied on the object balance the 200-N object and floats it. For this case, the value of buoyant force will be equal to the weight of the object.
[tex]F_b=W\\F_b=200\rm\; N[/tex]
Thus, the buoyant force on the object which floats with three-fourths of its volume beneath the surface of the water is 200 N.
Learn more about the buoyant force here;
https://brainly.com/question/3228409
In the past, Africa used to be further away from Europe than it is now
(shown below). What could explain why Africa is closer to Europe now than
it was before? *
Answer: Plates shifting
Explanation: After years and years of plates colliding into solid rock, they slowly become closer together. As recent studies have shown, Africa is currently moving closer to Europe one centimeter every year (one inch every 2.5 years).
Answer:
nvudbwasivnjlscv bwbfvsz
Explanation:
John decided to cycle to his friend's house at a speed of 5km/h and the journey took 2
hours. How far did John cycle?
Answer:100 miles
Explanation:
Answer:
10 Km
Explanation:
He is going 5km per hour and he arrived at his friend's house in 2 hours. You multiply 5 by 2 and you get 10.
An unknown radioactive sample is observed to decrease in activity by a factor of two in a one hour period. What is its half-life?
Answer:
The half-life is [tex] t_{1/2} = 1.005 h[/tex]
Explanation:
Using the decay equation we have:
[tex]A=A_{0}e^{-\lambda t}[/tex]
Where:
λ is the decay constantA(0) the initial activityA is the activity at time tWe know the activity decrease by a factor of two in a one hour period (t = 1 h), it means that [tex]A = \frac{A_{0}}{2}[/tex]
[tex]\frac{A_{0}}{2}=A_{0}e^{-\lambda*1 h}[/tex]
[tex]0.5=e^{-\lambda*1 h}[/tex]
Taking the natural logarithm on each side we have:
[tex]ln(0.5)=-\lambda[/tex]
[tex]\lambda=0.69 h^{-1}[/tex]
Now, the relationship between the decay constant λ and the half-life t(1/2) is:
[tex]\lambda = \frac{ln(2)}{t_{1/2}}[/tex]
[tex] t_{1/2} = \frac{ln(2)}{\lambda}[/tex]
[tex] t_{1/2} = \frac{ln(2)}{0.69}[/tex]
[tex] t_{1/2} = 1.005 h[/tex]
I hope it helps you!
find the vector parallel to the resultant of the vector A=i +4j-2k and B=3i-5j+k
Answer:
2008
Explanation:
2000+3+5======2008
Answer:
[tex]8\hat i-2\hat j-2\hat k[/tex]
Explanation:
Vectors in 3D
Given a vector
[tex]\vec P = P_x\hat i+P_y\hat j+P_z\hat k[/tex]
A vector [tex]\vec Q[/tex] parallel to [tex]\vec P[/tex] is:
[tex]\vec Q = k.\vec P[/tex]
Where k is any constant different from zero.
We are given the vectors:
[tex]\vec A = \hat i+4\hat j-2\hat k[/tex]
[tex]\vec B = 3\hat i-5\hat j+\hat k[/tex]
It's not specified what the 'resultant' is about, we'll assume it's the result of the sum of both vectors, thus:
[tex]\vec A +\vec B = \hat i+4\hat j-2\hat k + 3\hat i-5\hat j+\hat k[/tex]
Adding each component separately:
[tex]\vec A +\vec B = 4\hat i-\hat j-\hat k[/tex]
To find a vector parallel to the sum, we select k=2:
[tex]2(\vec A +\vec B )= 8\hat i-2\hat j-2\hat k[/tex]
Thus one vector parallel to the resultant of both vectors is:
[tex]\mathbf{8\hat i-2\hat j-2\hat k}[/tex]
An opera singer who is a baritone, lowers his pitch and raises his voice for a song. Which best describes how the resulting sound wave has changed? The sound wave will have:
a lower amplitude and higher wavelength
a lower amplitude and higher frequency.
a higher amplitude and lower frequency.
a higher amplitude and faster speed
Answer: 3.
Explanation:
The correct answer is a higher amplitude and lower frequency. Since an opera singer is lowering his pitch it means that he is creating higher amplitude and because he is raising his voice for a song with that higher amplitude he is creating lower frequency.
Paco pulls a 67 kg crate with 738 N and of force across a frictionless floor 9.0 M how much work does he do in moving the crate
Answer:
W = 6642 J
Explanation:
Given that,
Mass of a crate, m = 67 kg
Force with which the crate is pulled, F = 738 N
It is moved 9 m across a frictionless floor
We need to find the work done in moving the crate. Let the work done is W. It is given by :
W = F d
W = 738 N × 9 m
= 6642 J
So, the work done is 6642 J.
1. The mass of the Earth is 81 times the mass of the Moon. Using Newton's Law of Gravity, what would the effect of gravitation be if the mass of the Moon were increased by four times and the distance between Earth and
the Moon were cut in half?
Answer:
effects of gravity on the Moon and Earth
Explanation: Newton found the Moon's inward acceleration in its orbit to be 0.0027 metre per second per second, the same as (1/60)2 of the acceleration of a falling object at the surface of Earth.
As a bicycle is ridden west in a straight line with decreasing speed,the acceleration of the bicycle must be
Answer:
Decreasing
Hope this helps! :)
3
4
Lucy runs 4 meters to the east, then 5 meters south. What is the magnitude of her displacement?
Show Your Work
Answer:
The displacement is 6.4m
Explanation:
Step one:
given
we are told that Lucy runs 4 meters to the east,
then 5 meters south.
let the distance east be the displacement in the x-direction, and south be the y-direction
Step two:
The resultant of the x and y displacement is the magnitude of the total displacement z
applying Pythagoras theorem we have
z=√x^2+y^2
z=√4^2+5^2
z=√16+25
z=√41
z=6.4m
8) a 20kg box is sliding across the ground. If the coefficient of friction is 0.5, how much friction will the box experience?
A 490 N
B 19.6 N
C 98 N
D 2 N
Answer:
STOP CHETING
Answer:
C is the answer to your question
Explanation:
Have a great day!!! :)
PLEASE ans The question's in the pictures, please don't answer what already has answers. Only answer if you can finish both pages completely PLEASE I NEED HELP :(( if ur ans is relevant I will mark brainliest
While getting buff at the gym you lift a bunch of weights applying 1000N of force to lift them from the ground to a height of 2m. How much work did you do?
A. 2000 J
B. 1000J
C. -2000 J
D. -1000 J
if chilled coke and hot tea are
kept together tea cools down but ko gets warm why
What is the magnitude of the centripetal force that must be applied in order for a 2kg ball on a 2.0 m string to spin with uniform circular motion at 5.0 m/s
The ball needs to accelerate with a magnitude a (pointed towards the center of the circle) of
a = (5.0 m/s)² / (2.0 m) = 12.5 m/s²
Then the required tension F in the string would need to be
F = (2 kg) (12.5 m/s²) = 25 N
8x = -6. What does x equal?
Answer:
x=-3/4
Explanation:
Find the binding energy per nucleon for the plutonium isotope 239Pu. The mass of the neutral atom is 239.05216 u.
Answer:
The answer is "[tex]\bold{7.56 \ Me\ V}[/tex]".
Explanation:
calculating the binding energy on per nucleon:
calculating number of proton and neutrons:
proton [tex]P_u=94[/tex]
neutron[tex]= 239-94=145[/tex]
calculating mass:
proton mass [tex]\ m_P=1.007825 \ amu\\\\[/tex]
neutron mass [tex]\ m_n=1.008665 \ amu\\\\[/tex]
neutral atom mass [tex]m = 239.05216 \ amu\\\\[/tex]
mass of prtons[tex]= 94 \times 1.007825 = 94.73555 \ amu\\\\[/tex]
mass of neutrons[tex]= 145 \times 1.008665= 146.256425 \ amu\\\\[/tex]
Total nucleons mass formula:
[tex]\to m_n = (P+n)[/tex]
[tex]= 94.73555+ 146.256425\\\\= 240.991975 \ amu[/tex]
calculating the mass of defect:
[tex]\to \Delta m= m_n-m\\\\[/tex]
[tex]= 240.991975 - 239.05216\\\\= 1.939815 \ amu\\\\[/tex]
calculating the total of the binding energy:
[tex]\to BE=\Delta m\times 931.5 \ mev[/tex]
[tex]= 1.939815 \times 931.5\\\\=1806.938 \ Me \ V\\\\[/tex]
BE in per nucleon [tex]=\frac{BE}{239}= 7.56 \ Me\ V[/tex]
How high does a rocket have to go above the earth's surface to be subject to a gravitational field from the earth that is 50.0 percent of its value at the earth's surface?
A) 2.650 km
B) 3,190 km
C) 9.020 km
D) 12.700 km
Answer:
A) 2.650 km
Explanation:
The relationship between acceleration of gravity and gravitational constant is:
[tex]g = \frac{Gm}{R^2}[/tex] ---- (1)
Where
[tex]R = 6,400 km[/tex] -- Radius of the earth.
From the question, we understand that the gravitational field of the rocket is 50% of its original value.
This means that:
[tex]g_{rocket} = 50\% * g[/tex]
[tex]g_{rocket} = 0.50 * g[/tex]
[tex]g_{rocket} = 0.5g[/tex]
For the rocket, we have:
[tex]g_{rocket} = \frac{Gm}{r^2}[/tex]
Where r represent the distance between the rocket and the center of the earth.
Substitute 0.5g for g rocket
[tex]0.5g = \frac{Gm}{r^2}[/tex] --- (2)
Divide (1) by (2)
[tex]\frac{g}{0.5g} = \frac{Gm}{R^2}/\frac{Gm}{r^2}[/tex]
[tex]\frac{g}{0.5g} = \frac{Gm}{R^2}*\frac{r^2}{Gm}[/tex]
[tex]\frac{1}{0.5} = \frac{1}{R^2}*\frac{r^2}{1}[/tex]
[tex]2 = \frac{r^2}{R^2}[/tex]
Take square root of both sides
[tex]\sqrt 2 = \frac{r}{R}[/tex]
Make r the subject
[tex]r = R * \sqrt 2[/tex]
Substitute [tex]R = 6,400 km[/tex]
[tex]r = 6400km * \sqrt 2[/tex]
[tex]r = 6400km * 1.414[/tex]
[tex]r = 9 049.6\ km[/tex]
The distance (d) from the earth surface is calculated as thus;
[tex]d = r - R[/tex]
[tex]d = 9049.6\ km - 6400\ km[/tex]
[tex]d = 2649.6\ km[/tex]
[tex]d = 2650\ km[/tex] --- approximated
one newton equals 0.225
Students are using a mallet to hit a drum. The diagram below shows this action.
Drum
Drum
When the mallet
hits the drum,
the drum skin
begins to vibrate.
particles of air
compressed
together
particles of air
compressed
together
Mallet
particles of air
moving apart wave of
again
compressed
particles moving
outward
Which statement BEST describes the phenomenon illustrated in the model?
Sound waves are being transmitted through the air in the drum.
Sound waves are being transferred from the mallet to the drum.
O Sound waves are being absorbed by the drum.
Sound waves are being reflected by the drum.
Answer:
A
Explanation:
i think
A frequency generator sends a 550Hz sound wave through both water and ice. What is the difference in wavelength between the wave produced in ice and the wave produced in water?
Answer:
3.1
Explanation:
use formula f = v/lambda
