Answer:
Her speed at the bottom of the slide is 7.42 m/s
Explanation:
From the question,
The swimmer starts at rest, that is, her initial speed, u is 0 m/s.
Since she slides without friction and descends through a vertical height, then it is a free fall motion (due to gravity).
Also, from the question,
She descends through a vertical height of 2.81 m.
To determine her speed at the bottom of the slide, that is her final speed,
From one of the equations of motion for freely falling bodies
v² = u² + 2gh
Where v is the final speed
u is the initial speed
g is acceleration due to gravity (g = 9.8 m/s²)
and h is height
From the question,
u = 0 m/s
h = 2.81 m
Putting the values into the equation
v² = u² + 2gh
v² = 0² + 2×9.8×2.81
v² = 55.076
v =√55.076
v = 7.42 m/s
Hence, her speed at the bottom of the slide is 7.42 m/s.
Which material could be represented by the image above? (SC.8.P.8.1)
A. Diamonds
B. Milk
C. Oxygen
D. Wood
Answer:
a. diamonds
Explanation:
solid is the matter that has definite shape and definite volume. One good example is a diamond because contains particles that are strongly attract to each other.
whats a difference between a objects kinetic energy and potential energy
Answer:
A object having kinetic energy is in motion state.And the object whi posses potential energy i s in state of podition.
Answer:
Objects are relative to other moving and stationary objects.
Kinetic energy can be transferred from one moving object to another.
Potential energy is stored energy in an object.
A cup of hot coffee initially at 95 degrees C cools to 80 degrees C in 5 min while sitting in a room of temperature 21 degrees C. Using Newton's law of cooling, determine when the temperature of the coffee will be a nice 50 degrees C.
Answer:
When the temperature of the coffee is 50 °C, the time will be 20.68 mins
Explanation:
Given;
The initial temperature of the coffee T₀ = 95 °C
The temperature of the room = 21°C
Let T be the temperature at time of cooling t in mins
According to Newton's law of cooling;
[tex]\frac{dT}{dt} \alpha (T-21)\\\\\frac{dT}{dt} = k (T-21)\\\\\frac{dT}{T-21} = kdt\\\\\int\limits {\frac{dT}{T-21}} = \int\limits kdt\\\\Log(T-21) =kt + Logc \\\\Log (\frac{T-21}{c} ) = kt\\\\T -21 = ce^{kt}\\\\At \ t = 0, T = 95\\\\95-21 = ce^0\\\\74 = c\\\\New, equation: T -21 = 74e^{kt}\\\\Again; when \ t= 5\ min, T = 80\\\\80 -21 = 74e^{5k}\\\\59 = 74e^{5k}\\\\e^{5k} = \frac{59}{74}\\\\ 5k = ln(\frac{59}{74})\\\\5k = -0.2265\\\\k = -0.0453[/tex]
When the temperature is 50 °C, the time t in min is calculated as;
[tex]T -21 = 74e^{-0.0453t}\\\\50 -21 = 74e^{-0.0453t}\\\\29 = 74e^{-0.0453t}\\\\\frac{29}{74} = e^{-0.0453t}\\\\0.39189 = e^{-0.0453t}\\\\ln(0.39189 ) = {-0.0453t}\\\\-0.93677 = {-0.0453t}\\\\t = \frac{-0.93677}{-0.0453}\\\\ t = 20.68 \ mins[/tex]
Therefore, when the temperature of the coffee is 50 °C, the time will be 20.68 mins
In 10 minutes the hot coffee will attain the temperature of 50 degrees Celsius.
Initially the hot cup of coffee at the temperature of 95 degrees Celsius but after 5 minutes its temperature decreases from 95 to 85 degrees Celsius which is 15 degrees Celsius decrease so in other 5 minutes, the temperature decreases to 65 degrees Celsius.
Again after 5 minutes the temperature will further decrease finally the cup of coffee attain the temperature of 50 degrees Celsius so we can conclude that in 10 minutes the hot coffee will gain the 50 degrees Celsius temperature.
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Derivation 1.2 showed how to calculate the work of reversible, isothermal expansion of a perfect gas. Suppose that the expansion is reversible but not isothermal and that the temperature decreases as the expansion proceeds. (a) Find an expression
Answer:
(a) The work done by the gas on the surroundings is, 17537.016 J
(b) The entropy change of the gas is, 73.0709 J/K
(c) The entropy change of the gas is equal to zero.
Explanation:
(a) The expression used for work done in reversible isothermal expansion will be,
where,
w = work done = ?
n = number of moles of gas = 4 mole
R = gas constant = 8.314 J/mole K
T = temperature of gas = 240 K
= initial volume of gas =
= final volume of gas =
Now put all the given values in the above formula, we get:
The work done by the gas on the surroundings is, 17537.016 J
(b) Now we have to calculate the entropy change of the gas.
As per first law of thermodynamic,
where,
= internal energy
q = heat
w = work done
As we know that, the term internal energy is the depend on the temperature and the process is isothermal that means at constant temperature.
So, at constant temperature the internal energy is equal to zero.
Thus, w = q = 17537.016 J
Formula used for entropy change:
The entropy change of the gas is, 73.0709 J/K
(c) Now we have to calculate the entropy change of the gas when the expansion is reversible and adiabatic instead of isothermal.
As we know that, in adiabatic process there is no heat exchange between the system and surroundings. That means, q = constant = 0
So, from this we conclude that the entropy change of the gas must also be equal to zero.
Explanation:
HELP PLEASE!!!
If we have a sample of silicon (Si) atoms that has 14 protons, 14 electrons, and 18 neutrons
What is the name of this specific silicon isotope?
si-14
si-32
si-46
si-153
Answer:
It is si-32
Explanation:
Answer:
silicon-32
Explanation:
just took the quiz and got it right
what happens to the temperature of water as time elapses? IF YOU ANSWER IT I WILL MARK YOU A BRAINLEST ANSWER
Answer:
I think it will get colder
Explanation:
Answer:
The water molecules go faster as it gets colder they go slower
Explanation:
trust me thats the answer
Concerning the work done by a conservative force, which of the following statements, if any, are true? It can always be expressed as the difference between the initial and final values of a potential energy function. It is independent of the path of the body and depends only on the starting and ending points. When the starting and ending points are the same, the total work is zero.
Answer:
It is independent of the path of the body and depends only on the starting and ending points.
Explanation:
In Physics we define a conservative force as a force that is independent of the path of the body and depends only on the starting and ending points.
For conservative forces we can write;
KEi + PEi = KEf +PEf
where;
KEi= initial kinetic energy
PEi= initial potential energy
KEf= final kinetic energy
PEf= final potential energy
This equation is known as the principle conservation of mechanical energy . It applies only to conservative forces where friction is negligible. The term KE + PE is also known as the total mechanical energy of the system.
When electrical energy is used what type of energy is also produced and considered to be waste energy?
Radiant energy
Thermal energy
Mechanical energy
Nuclear energy
Answer:
Thermal Energy
Explanation:
A car takes 8 s to increase its velocity from 10 m/s to
30 m/s. What is its average acceration?
Answer:
Average acceleration is 2.5 m/s^2.
Explanation:
Average acceleration can be found by dividing the change in speed by the change in time.
We know that the initial velocity=10m/s, the final velocity=30m/s and time elapsed is t=8s.
a= (Final velocity-Initial Velocty)/t
a=(30-10)/8=20/8=2.5 m/s^2
The world’s fastest car can accelerate from rest to 60 mph(27m/s) in 2.2 seconds. What is the magnitude of its acceleration?
Hi there! :)
12.27 m/s²Find the acceleration by finding the change in velocity over time:
(vf - vi) / (time) = acceleration over the interval
*Remember, an object at rest has a velocity of 0 mph, and use the correct units for speed that would result in an acceleration involving meters / seconds.*
(27 - 0) / (2.2) = 27 / 2.2 ≈ 12.27 m/s²
There are 5.5 L of a gas present at -38.0 C. What is the temperature if the volume of the gas has changed to 1.30 L?
Answer:
We are given:
V1 = 5.5L T1 = -38 C or 235 k
V2 = 1.3L T2 = T
From the gas equation:
PV = nRT
Since the pressure (P) , number of moles (n) and the universal gas constant (R) are constants, we can write the same equation as:
V / T = k (where k is a constant)
so a bit more insight, since the values noted above are constant, when multiplied by each other, they will provide us with a constant number irrespective of the value of the variables
Changing the variables for the first case:
V1 / T1 = k (where k is the same constant) ----------------(1)
Similarly,
V2 / T2 = k (again, k has the same value)----------------(2)
From (1) and (2):
k is the common value
V1 / T1 = V2 / T2
Replacing the variables
5.5 / 235 = 1.3 / T
T = 1.3 * 235 / 5.5
T = 55.54 k
Therefore, at 55.54 K the gas will have a volume of 1.3L
Super Mario and Bowser Jr. are racing around a track when Baby Bowser launches a green shell at Mario, bringing him to rest. Bowser Jr. then passes Mario at his top speed of 30 blocks/h, moving down the track in a straight line. Mario quickly accelerates and reaches his top speed of 40 blocks/h in order to catch back up and pass Bowser Jr., but by this point he has opened up a 75 block head start down the track. Mario world measure distance using the units of blocks, with 1 block = 0.47 m.
a) What are Mario and Bowser Jr.'s speeds in m/s?
Assuming both Mario and Bowser Jr. race to the finish in a straight line at their top speeds,
b) How long does it take for Mario to catch Bowser Jr.?
c) How far down the track is Mario from the point at which he reaches his top speed?
Answer:
(a). Mario's speed in m/s = 5.2 × 10^-3 m/s.
Bowser Jr.'s speeds in m/s = 3.92 × 10^-3 m/s.
(b). 27001.2 seconds(s)..
(c). 141 metre(m).
Explanation:
So, the following data or parameters or information was given in the question above. These informations are going to help us in solving this question or problem;
=>" Bowser Jr. then passes Mario at his top speed = 30 blocks/h.
=> " Mario quickly accelerates and reaches his top speed of 40 blocks/h in order to catch back up and pass Bowser Jr., but by this point he has opened up a 75 block head start down the track."
=> "Mario world measure distance using the units of blocks, with 1 block = 0.47 m"
Therefore, the solution is given below;
(1). For the first part, we are to determine or calculate Mario and Bowser Jr.'s speeds in m/s.
Therefore, Mario's speed in m/s = 40 × 0.47) ÷ 3600 = 5.2 × 10^-3 m/s.
Also, Bowser Jr.'s speeds in m/s = ( 30 × 0.47) ÷ 3600 = 3.92 × 10^3 m/s.
(2). So, the next thing to do now.is to determine or calculate how long it took for Mario to catch Bowser Jr.
Thus, the time it took for Mario to catch Bowser Jr. Can be related as below;
[ ( 5.2 × 10^-3 m/s) - (3.92 × 10^-3 m/s) × (time,t taken for Mario to catch Bowser Jr.) = 75 × 0.47.
Therefore, the time it took for Mario to catch Bowser Jr. = 27001.2 seconds.
(3). Now, we calculate How far down the track Mario from the point at which he reaches his top speed.
The distance = 5.2 × 10^-3 m/s × 27001.2m = 141m
A student uses a microwave oven to heat a meal. The wavelength of the radiation is 8.97 cm. What is the energy of one photon of this microwave radiation? Multiply the answer you get by 1025 to be able to input a number more easily into canvas. Enter to 2 decimal places.
Answer:
The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
Explanation:
The energy (E) of a photon is:
[tex] E = h\frac{c}{\lambda} [/tex]
Where:
h: is the Planck's constant = 6.62x10⁻³⁴ J.s
λ: is the wavelength of the radiation = 8.97 cm
c: is the speed of light = 3.00x10⁸ m/s
[tex] E = h\frac{c}{\lambda} = 6.62 \cdot 10^{-34} J.s\frac{3.00\cdot 10^{8} m/s}{8.97 \cdot 10^{-2} m} = 2.21 \cdot 10^{-24} J [/tex]
Hence, the energy of one photon is 2.21x10⁻²⁴ J.
Now, if we multiply the answer by 10²⁵ we have:
[tex] E = 2.21 \cdot 10^{-24} J \cdot 10^{25} = 22.10 J [/tex]
I hope it helps you!
The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
Calculation of energy:We know that
[tex]E = h\frac{c}{\lambda}[/tex]
Here
h be the Planck's constant = 6.62x10⁻³⁴ J.s
λ be the wavelength of the radiation = 8.97 cm
c be the speed of light = 3.00x10⁸ m/s
Now
Here we need to multiply the answer 10^25 so that the correct answer could come.
[tex]E = 6.62.10^{-34} \frac{3.00.10^{8}}{8.97.10^{-2}}[/tex]
= 2.21x10⁻²⁴ J.
= 22.10 J.
Hence, the energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
learn more about energy here; https://brainly.com/question/24719731
What is the volume of an object if it has a mass of 10 grams and a density of 87 g/ml
Answer:
The answer is 0.115 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 10 g
density = 87 g/ml
We have
[tex]volume = \frac{10}{87} \\ = 0.114942528...[/tex]
We have the final answer as
0.115 mLHope this helps you
What would be the speed of an object just before hitting the ground if dropped 100 meters?
We are given:
the initial height of the object (h) = 100 m
initial velocity (u) = 0 m/s
we will let the value of g = 10 m/s/s
Speed of the object just before hitting the ground:
From the third equation of motion:
v² - u² = 2ah (where v is the final velocity)
replacing the variables, we get:
v² - (0)² = 2(10)(100)
v² = 2000
v = 10√20 = 44.7 m/s
Therefore, the speed of the object just before hitting the ground is 44.7 m/s
An airplane flies with a constant speed of 600 km/h. to the west. How far can it travel in 1/4 hour?
Answer:
d = 150 km
Explanation:
Speed of an airplane is 600 km/h
We need to find how far it travel in 1/4 hour.
We know that the speed of an object is given by distance travelled divided by the time taken. Let d is the distance covered in 1/4 hour. So,
[tex]v=\dfrac{d}{t}\\\\d=v\times t\\\\d=600\ km/h \times \dfrac{1}{4}\ h\\\\d=150\ km[/tex]
So, it will cover 150 km.
A ray is incident at at 50 degrees angle on a plane mirror. What will be the deviation after reflection from the mirror?
Answer:
Explanation:
If the ray were not deviated, it would travel straight through the mirror. Due to the mirror, the incident ray is reflected at 30°. The ray travels 30° + 30° = 60°. The angle of deviation is 180° - 60° = 120°.
50 POINTS!!! PLEASE!!!!!! Pls help me with this been stuck on it in like FOREVER!! PLSS.
Answer:
it will move in 356.5g in diagonal direction(resultant or between the both direction)
Explanation:
285+428/2=356.5g
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how do you Convert 50 g to kg in an equation for physics
Answer:
Divide by 1000
Explanation:
Converting compound units
You would like to know whether silicon will float in mercury and you know that can determine this based on their densities. Unfortunately, you have the density of mercury in units of kilogram/meter3 and the density of silicon in other units: 2.33 gram/centimeter3. You decide to convert the density of silicon into units of kilogram/meter3 to perform the comparison. By which combination of conversion factors will you multiply 2.33 gram/centimeter3 to perform the unit conversion?
Answer:
Dividing the silicon density by 1000 and then multiply it by 1000000.
Explanation:
A kilogram equals 1000 grams and a cubic meter equals 1000000 cubic centimeters. Hence, we must divide the silicon density by 1000 and then multiply itby 1000000 to convert the value into kilograms per cubic centimeter. That is:
[tex]x = 2.33\,\frac{g}{cm^{3}}\times \frac{1\,kg}{1000\,g}\times \frac{1000000\,cm^{3}}{1\,m^{3}}[/tex]
[tex]x = 2330\,\frac{kg}{m^{3}}[/tex]
In a nutshell, we must multiply the density of silicon by 1000 to obtains its value in kilograms per cubic meter.
The speed of a car is decreasing from 35 m/s to 15 m/s in 4s
Which object will require the greatest amount of force to change its motion?
A. A 148 kg object moving 131 m/s
B. A 153 kg object moving 127 m/s
C. A 160 kg object moving 126 m/s
O D. A 162 kg object moving 124 m/s
Answer: D 160kg object moving 126 m/s
Explanation:
An object having a mass of 162 kg and moving with a velocity of 124 m/sec will require the greatest amount of force to change its motion. The correct option is D.
What is force?Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.
If the object has to stop, the final velocity must be zero. If the time is constant, the amount of force only depends on the mass and the velocity at which the body is moving.
The amount of force on the object depends on the momentum of the body.
The momentum of the body is;
P = mv
Object D will require the greatest amount of force to change its motion. Because the momentum of the body for option D is the greatest.
Hence, the correct option is D.
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Take the regular compass and hold it so the case is vertical. Now use it to investigate the direction of the coil’s magnetic field at locations other than the central axis. What happens as you move away from the center axis toward the coil? What happens above the coil? Outside the coil? Below the coil?
Answer:
Please find the answer in the explanation
Explanation:
Take the regular compass and hold it so the case is vertical. Now use it to investigate the direction of the coil’s magnetic field at locations other than the central axis.
What happens as you move away from the center axis toward the coil? The direction of the magnetic compass needle will move in an opposite direction since the direction of the induced voltage is reversed.
What happens above the coil?
the needle on the magnetic compass will be deflected. Since compasses work by pointing along magnetic field lines
Outside the coil? The magnetic compass needle will experience no deflection. Since there is no induced voltage or current.
Below the coil?
The needle will move in an opposite direction.
Write a haiku
poem
explaining
why graphing
is useful.
If you are
able, share
your poem
with others.
Answer:
Explanation:
graphing is helpful
helps visualize the line
of your equation
first correct answer gets brainliest
Answer:
electrical energy transforming into sound energy in speaker
Answer:
the first one. Electrical energy transforming into sound energy in a speaker
Can someone please explain how to find the acceleration of the hanging mass?
Answer:
Acceleration = m/s²
Explanation:
T= Newtons compared to the weight W = Newtons for the hanging mass. If the weight of the hanging mass is less than the frictional resistance force acting on the mass on the table, then the acceleration will be zero.
the neuron is considered a (a. Cell. (B.artery. (C. Vein
Answer:
A Cell
Explanation:
A man walking at 3.56 m/s accelerates at 2.50 m/s2 for 9.28 s. How far does he get?
141 m
26.8 m
44.6 m
248 m
I need to write 200 words about: boys are most influenced by their fathers and girls are most influenced by their mothers. Do you agree or disagree?
Answer:
I agree
Explanation:
I agree because most of the times girls pass more time with their mom since they hace more things in common, it’s the same with the boys.
how far will a brick starting from rest fall freely in 3.0 seconds?
Answer: It will be about 44.1m
Explanation: