Answer:
t ’= [tex]\frac{1450}{0.6499 + 2 v_r}[/tex], v_r = 1 m/s t ’= 547.19 s
Explanation:
This is a relative velocity exercise in a dimesion, since the river and the boat are going in the same direction.
By the time the boat goes up the river
v_b - v_r = d / t
By the time the boat goes down the river
v_b + v_r = d '/ t'
let's subtract the equations
2 v_r = d ’/ t’ - d / t
d ’/ t’ = 2v_r + d / t
[tex]t' = \frac{d'}{ \frac{d}{t}+ 2 v_r }[/tex]
In the exercise they tell us
d = 1.22 +1.45 = 2.67 km= 2.67 10³ m
d ’= 1.45 km= 1.45 1.³ m
at time t = 69.1 min (60 s / 1min) = 4146 s
the speed of river is v_r
t ’= [tex]\frac{1.45 \ 10^3}{ \frac{ 2670}{4146} \ + 2 \ v_r}[/tex]
t ’= [tex]\frac{1450}{0.6499 + 2 v_r}[/tex]
In order to complete the calculation, we must assume a river speed
v_r = 1 m / s
let's calculate
t ’= [tex]\frac{ 1450}{ 0.6499 + 2 \ 1}[/tex]
t ’= 547.19 s
Please give a step by step explanation: 30 points up for grabs.
Answer:
Honestly, I don't know ¯\_(ツ)_/¯
Explanation:
regular reflection is the reflection of light on a surface
on smooth surface like mirror.
Binding energy is the energy needed to
a. keep the electrons spinning around the nucleus of an atom.
b. keep the atoms in a covalent compound together.
c. keep the atoms in example of an element together.
d. hold the nucleus of an atom together.
Answer:
Answer C
Explanation:
Suppose that the acceleration of a model rocket is proportional to the difference between 160 ft/sec and the rocket's velocity. If it is initially at rest and its initial acceleration is 280 ft/sec22, how long will it take to accelerate to 128 ft/s
Answer:
Explanation:
Given ,
dv / dt = k ( 160 - v )
dv / ( 160 - v ) = kdt
ln ( 160 - v ) = kt + c , where c is a constant
when t = 0 , v = 0
Putting the values , we have
c = ln 160
ln ( 160 - v ) = kt + ln 160
ln ( 160 - v / 160 ) = kt
(160 - v ) / 160 = [tex]e^{kt}[/tex]
1 - v / 160 = [tex]e^{kt }[/tex]
v / 160 = 1 - [tex]e^{kt }[/tex]
v = 160 ( 1 - [tex]e^{kt }[/tex] )
differentiating ,
dv / dt = - 160k [tex]e^{kt }[/tex]
acceleration a = - 160k [tex]e^{kt }[/tex]
given when t = 0 , a = 280
280 = - 160 k
k = - 175
a = - 160 x - 175 [tex]e^{kt}[/tex]
a = 28000 [tex]e^{kt}[/tex]
when a = 128 t = ?
128 = 28000 [tex]e^{kt}[/tex]
[tex]e^{kt }[/tex] = .00457
Acceleration of a rocket model.
As acceleration is the change in the magnitude and direction of the moving body and refers to the increase in the velocity which varies over time. The acceleration of the model rocket is proportional to the r difference between the 160 feet/sec.
Thus the answer is 0.0457
The initial velocity of the rockset at the rest and the initial acceleration is about 280 fett/ sec then the length of acceleration for the rokst to reach 128 feet / sec. Will be calculated by the dv / dt = k ( 160 - v ).ln ( 160 - v ) = kt + c , where c is a constant, when t = 0 , v = 0 then putting the values , we have c = ln 160ln ( 160 - v ) = kt + ln 160, ln ( 160 - v / 160 ) = kt(160 - v ) / 160 = 1 - v / 160 = v / 160 = 1 - v = 160 ( 1 - ) acceleration a = - 160k given when t = 0 , a = 280 The 280 = - 160 k, k = - 175 a = - 160 x - 175 Hence a = 2800Thus 128 = 28000 = .00457.Learn more about acceleration.
brainly.com/question/13137118.
A 0.54 kg air hockey puck is initially at rest. What will it's kinetic energy energy be after a net force of 0.56 N acts on it for a distance of 0.84m?
Answer:
Kf = 470 mJ
Explanation:
According the work-energy theorem, the change in the kinetic energy of one object, is equal to the net work done on it.Since the puck is initially at rest, the change is kinetic energy is just the final kinetic energy of the puck.Assuming that the net force is horizontal, and causes a horizontal displacement also, we can find the net work on the puck as follows:[tex]W_{net} = F_{net} * \Delta X = 0.56 N * 0.84 m = 0.47 J = 470 mJ (1)[/tex]
As we have already said, (1) is equal to the final kinetic energy of the puck:⇒ Kf = 470 mJ (2)is found in wood or straw?*
2.
Sucrose
2.Xylose
3.Maltose
4.Galactose
A light spring of force constant 3.85 N/m is compressed by 8.00 cm and held between a 0.250 kg block on the left and a 0.500 kg block on the right. Both blocks are at rest on a horizontal surface. The blocks are released simultaneously so that the spring tends to push them apart. What is the maximum velocity each block attains if the coefficient of kinetic friction between each block and the surface is:_______.
A) 0
B) 0.100
C) 0.463
Assume that the coefficient of static friction is larger than that for kinetic friction.
Answer:
A) v1 = -0.256 m/s
v2 = 0.128 m/s
B) v1 = -0.0642 m/s
v2 = 0 m/s
C) v1 = v2 = 0 m/s
Explanation:
We are given;
Spring constant; k = 3.85 N/m
Distance compressed; x = 8 cm = 0.08 m
Mass of left block; m1 = 0.25 kg
Mass of right block; m2 = 0.5 kg
A) From conservation of energy;
½kx² = ½m1•v1² + ½m2•(v2)²
Also from conservation of linear momentum, we know that;
m1v1 = m2v2
Now, v2 = m1•v1/m2
Plugging this for v2 in the first equation gives;
½kx² = ½m1•v1² + ½m2•(m1•v1/m2)²
Making v1 the subject, we have;
v1 = √(kx²(m2))/(m1•m2 + (m1)²))
v1 = √[(3.85 × 0.08² × 0.5)/((0.25 × 0.5) + 0.5²))
v1 = 0.256 m/s
This is the left block which is in the negative x direction and so v1 = -0.256 m/s
We saw that v2 = m1•v1/m2
Thus; v2 = (0.25 × 0.256)/0.5
v2 = 0.128 m/s
B) Force exerted by spring is;
F_s = kx = 3.85 × 0.08
F_s = 0.308 N
Normal forces will be calculated for both blocks as;
N1 = m1•g = 0.25 × 9.8 = 2.45 N
N2 = m2•g = 0.5 × 9.8 = 4.9 N
Let's calculate force of static friction for both blocks;
F_s1 = μN1 and F_s2 = μN2
We are given coefficient of friction as
μ = 0.1.
Thus;
F_s1 = 0.1 × 2.45 = 0.245 N
F_s2 = 0.1 × 4.9 = 0.49 N
F_s1 is lesser than F_s. Thus let's calculate the new compression;
x_1 = 0.245/3.85
x_1 = 0.06364 m
Thus, change in compression is;
Δx = x - x_1
Δx = 0.08 - 0.06364
Δx = 0.01636 m
From conservation of energy, since our coefficient of friction is not zero and we have frictional force, then we use the equation;
½k(x)² - F_s1•Δx = ½m1•v1² + ½k(x_1)²
Making v1 the subject, we have;
v_1 = √(k(x² - x_1²) - 2F_s1•Δx)/m1
v_1 = √(3.85(0.08² - 0.06364²) - 2(0.245 × 0.01636)/0.25
v1 = 0.0642 m/s
Since in negative x direction, then
v1 = -0.0642 m/s
F_s2 is greater than F_s. Thus, it means the right side block will not move and velocity is zero. v2 = 0 m/s
C) Coefficient of friction is now 0.463.
Thus;
F_s1 = 0.463 × 2.45 = 1.13435 N
F_s2 = 0.463 × 4.9 = 2.2687 N
They are both greater than F_s and thus no motion in both cases.
So v1 = v2 = 0 m/s
I 2016 there were fewer pedestrians killed in traffic crashes than during the previous year
how many carbon (C) atoms are in a molecule of CH2O?
Answer:1 carbon atom
Explanation:AP3X
Answer:
1
Explanation:
A weightlifter lifts a weight of 500 N from the ground over her head, a distance of 1.8 m. How much work has been done to move the weight?
A boy throws a rock with an initial horizontal velocity of 17.0 m/s and an initial vertical velocity of 21.0 m/s. How high above the boy's hand is the rock after 2.8 s?
Answer:
53.2
Explanation:
You can use the kinematic equation: displacement of x = (initial velocity + final velocity)*t/2
Subsititing: 17+21 = 38 * 2.8/2 = 53.2
Note: Displacement = distance between the 2 points
The degree of relationship between two or more variables is _________.
Can someone help me grasp the concept of solving this please
Answer:
Q= m × c × change in tempQ= 1000 cal/kg × C Q= (5kg) × (1000 ) × (100-13) Q= 435000Hence 4.35 × 10^5 Ask any questions!I also do quizzes and exams if your interested!What force balances gravity as the balloon sticks to the sticks to the wall?
Answer:
thats answer
Explanation:
please give me a brainlyliest
S
m
On a frictionless toy race track, a 0.035 kg toy car moving right at 0.30 collides with another 0.040 kg toy
m
car moving left at 0.20 After the collision, the 0.035 kg car moves left at 0.20
S
m
S
What is the final speed of the 0.040 kg toy car?
Answer: 0.24 m/s
Explanation:
The temperature of stars in the universe varies with the type of star and the age of the star among other things. By looking at the shape of the spectrum of light emitted by a star, we can tell something about its average surface temperature.i)If we observe a star's spectrum and find that the peak power occurs at the border between red and infrared light, what is the approximate surface temperature of the star
Answer:
T = 3.6 10³ K
Explanation:
A good way to calculate the surface temperature of a star is to approximate it as a black body, and use Wien's displacement law.
λ T = 2,898 10⁻³
In this case they tell us that the light from the star is between red (700nm) and light infrared (2500nm) suppose that the radiation is
λ = 800 nm (near infrared)
T = 2,898 10⁻³ /λ
T = 2,898 10⁻³/ (800 10⁻⁹)
T = 3.6 10³ K
You toss a ball into the air and note the time interval between the ball leaving your hand and reaching its highest position. While you are doing this, a construction worker being lifted on a hydraulic platform at constant speed also notes the time interval needed for the ball to reach its highest position. Is the time interval reported by the worker longer, shorter, or the same as the interval you report?
Answer:
It is longer
Explanation:
According to the theory of special relativity, moving clocks run slower. So, the construction worker moving at a constant speed observers a time much longer than the time I observe since I am stationary. If t is the time observed by me and v is the speed of the construction worker, then, the time observed by the construction worker, t' is given by
t' = t/√[1 - (v/c)²] where c = speed of light
So, the construction worker reports a longer time interval than me since his time runs slower.
The diameter of the Earth is about 13,000km. The diameter of the moon is about 3,500km. If the student makes her model of the Earth 26mm in diameter, what should be the diameter of her model of the moon in mm?
Identify the labeled parts in the figure.
i. Which of the labeled parts is a chemical symbol?
ii. Which of the labeled parts is a coefficient?
iii. Which of the labeled parts is the number of atoms of the element?
iv. Which of the labeled parts indicates that only one atom of the element is present in the substance?
Answer:
I. a, c, f and h
II. e
III. b, d, g and i
IV. i
Explanation:
I. Chemical symbols are simple abbreviations used to represent various elements or compound. They consist entire of alphabet.
For the diagram given above, the labelled parts which represent chemical symbol are: a, c, f and h
II. Coefficients are numbers written before the chemical symbol of elements or compound.
For the diagram given above, the labelled part which represent Coefficient is: e
III. Number of atoms of element present in a compound is simply obtained by taking note of the numbers written as subscript in the chemical formula of the compound.
For the diagram given above, the labelled part which represent the number of atoms of the element are: b, d, g and i
IV. When no number is written as subscript in the formula of the element in the compound, it means the element has just 1 atom in the compound.
For the diagram given above, the labelled part which indicates that only 1 atom of the element is present is: i
Answer:
i. a, c, f, h
ii. e
iii. b, d, g, i
iv. i
camouflage is to blend in with what
Answer:
Camouflage is a way of hiding. Blending in.
Explanation:
Look it up in a dictionary
In which situation would a bicycle rider NOT be accelerating?
If her direction changed and speed was constant.
If her speed decreased.
If her direction and speed were unchanged.
If her speed increased and direction was unchanged.
Answer:
If her direction and speed were unchanged.
Explanation:
Acceleration is a vector, so it has magnitude and direction.
If direction changes, acceleration exists.
If speed changes, acceleration exists.
50 Points, It is about Inquiry, Experiment, Controlled Variable, Independent Variable, Hypothesis, and Dependent Variable.
Answer:
1) dependent
2) Experiment
3) Controlled variable
4) hypothesis
5) Inquiry
Explanation:
The dependent variables are those variables that change when the experimental or independent variable is being manipulated.
An experiment is a carefully designed study that tends to establish a cause and effect relationship between two or more variables.
A control variable is any variable which is held constant or unchanged throughout the course of the investigation(experiment).
Hypothesis is a precise statement which can be tested and predicts the outcome of the study.
The independent variable is the variable that is being manipulated.
How much is the frequency of gold?
Answer:
316 Hz
Explanation:
As for Frequencies of Elements, Gold is said to have 316 Hz
Answer:
The frequency of gold is 316 Hz
Explanation:
Since ancient times, gold is high valued and in the middle ages gold was experienced from the masters of alchemy not only for becoming rich, but also for healing purposes, as from Paracelsus and others.
A 0.38 kg drinking glass is filled with a hot liquid. The liquid transfers 7032 J of energy to the glass. If the
temperature of the glass increases by 22 K, what is the specific heat of the glass?
Answer:
841 J/kg.K
Explanation:
The computation of the specific hear of the glass is shown below:
As we know that
E= cmΔt
where
c denotes specific heat
m denotes 0.38 kg
Δt = temperature = 22k
E denotes energy = 7032 J
Now
7032 J = (0.38) (22) (c)
7032 J = 8.36 (c)
So C = 7032 J ÷ 8.36
= 841 J/kg.K
As a space shuttle moves through the dilute ionized gas of Earth's ionosphere, the shuttle's potential is typically changed by -1.5 V during one revolution. Assuming the shuttle is a conducting sphere of radius 11 m, estimate the amount of charge it collects.
Radioactive strontium (Sr) is harmful to humans. Strontium, when ingested by cows, can be introduced to milk through the process of replacing an element of the same group or family that has similar properties. Using the Periodic Table, which element do you think can be easily replaced by strontium in milk?
A: B
B: Ag
C: Ca
D: K
Answer:
Ca
Explanation:
It is
A person on shore sees light
coming from a fish underwater. In
air, the ray travels at 21.2 deg. At
what angle did the ray travel
underwater?
Resources
Help
(Water n = 1.33, Air n = 1.00)
t
ti
(Unit = deg)
Answer:
15.7
Explanation:
Since N1 sin(angle1)= N2 sin(angle2), you can set up the equation to find the missing angle using inverse sin( 1.00 sin(21.2)/ 1.33). You would then get that the other angle is equal to 15.7 or 15.8 if you round up. I hope this helped! :)
Answer:
15.7
Explanation:
Acellus
Which plate is the South American plate?
Answer:
The south American plate
There are two categories of ultraviolet light. Ultraviolet A (UVA) has a wavelength ranging from 320 nmnm to 400 nmnm. It is not so harmful to the skin and is necessary for the production of vitamin D. UVB, with a wavelength between 280 nmnm and 320 nmnm, is much more dangerous, because it causes skin cancer.
Required:
a. Find the frequency ranges of UVA and UVB.
b. What are the ranges of the wave numbers for UVA and UVB?
Answer:
a) Remember the relationship:
v = f*λ
where:
v = velocity of the wave, remember that for an electromagnetic wave, this always is equal to the speed of light, then:
v = c = 3*10^8 m/s
f is the frequency of the wave
λ is the wavelength.
So if we want to compute the frequency, we have the equation:
f = c/λ
then:
We know that UVA has the range from 320 nm to 400nm, converting these to meters we hav:
1nm = 1m*10^(-9)
then:
320mm = (320*10^(-9)) m = 0.00000032 m
400nm = (400*10^(-9)) m = 0.00000040 m
Replacing these in our equation we can find that the range of frequencies is:
f = (3*10^8 m/s)/( 0.00000032 m) = 9.375*10^(14) Hz
f = (3*10^8 m/s)/( 0.00000040 m) = 7.5*10^(14) Hz
Then the range of frequencies is:
( 7.5*10^(14) Hz to 9.375*10^(14) Hz)
Similar for the case of UVB:
the wavelengths are:
280 nm to 320 nm
Rewriting these in meters we get:
280nm = 280*10^(-9) m = 0.00000028m
320nm = 320*10^(-9) m = 0.00000032 m
Then the frequencies are:
f = (3*10^8 m/s)/( 0.00000032 m) = 9.375*10^(14) Hz
f = (3*10^8 m/s)/( 0.00000028 m) = 1.07*10^(15) Hz
The range of frequencies for UVB is:
(9.375*10^(14) Hz to 1.07*10^(15) Hz)
B) We want to know the range of wavenumbers for both types of waves.
The wave number is calculated as:
1/λ
Which represents the number of waves in a given unit of length.
Then the range for UVA will be:
1/320nm = 0.0031 nm^-1
1/400nm = 0.0025 nm^-1
Then the range is:
( 0.0025 nm^-1, 0.0031 nm^-1)
And for the case of UVB we will have:
1/320 nm = 0.0031 nm^-1
1/280 nm = 0.0036 nm^-1
Then the range is:
(0.0031 nm^-1, 0.0036 nm^-1)
The left fielder throws the baseball home from 60 m away. The ball's horizontal velocity is 30 m/s, and its vertical velocity is sufficient to keep it in the air until it reaches the catcher at home plate. At the same time, a base runner is running toward home plate. His velocity is 5 m/s, and he is 5 m from home plate. If the base runner's velocity stays constant and air resistance isn't a factor, which will arrive at home plate first, the base runner or the baseball?
Answer:
The base runner
Explanation:
To know the correct answer to the question, we shall determine the time taken for the baseball and the base runner to get to the home plate. This is illustrated below:
For the baseball:
Horizontal velocity (u) = 30 m/s
Horizontal distance (s) = 60 m
Time (t) =?
s = ut
60 = 30 × t
Divide both side by 30
t = 60 / 30
t = 2 s
Thus, it will take the baseball 2 s to get to the home plate.
For the base runner:
Horizontal velocity (u) = 5 m/s
Horizontal distance (s) = 5 m
Time (t) =?
s = ut
5 = 5 × t
Divide both side by 5
t = 5 / 5
t = 1 s
Thus, it will take the base runner 1 s to get to the home plate.
SUMMARY:
Time taken for the baseball to get to the home plate = 2 s
Time taken for the base runner to get to the home plate = 1 s
From the calculations made above, we can conclude that the base runner will arrive at the home plate first because it took him 1 s to get to the home plate whereas the baseball took 2 s to get there.