Answer:
The hotter star radiates 625 times more energy per second from each square meter of its surface
Explanation:
Temperature of the hotter star is 30000 K
temperature of the cooler star = 6000 K
From Stefan-Boltzmann radiation laws, for a non black body
P = εσA[tex]T^{4}[/tex]
where
P is the energy per second or power of radiation
ε is the emissivity of the body
σ is the Stefan-Boltzmann constant of proportionality
A is the area of the sun
T is the temperature of the sun
The sun can be approximated as a black body, and the equation reduces to
P = σA[tex]T^{4}[/tex]
For the hotter body,
P = σA([tex]30000^{4}[/tex]) = 8.1 x 10^17σA J/s
For the cooler body,
P = σA([tex]6000^{4}[/tex]) = 1.296 x 10^15σA J/s
comparing the two stars energy
==> (8.1 x 10^17)/(1.296 x 10^15) = 625
This means that the hotter star radiates 625 times more energy per second from each square meter of its surface
A projectile is fired from a height of 80 M above sea level, horizontally with a speed of 360 M / S, calculate: The time it takes for the projectile to reach the water. The Horizontal scope. The height that remains to descend after 2 seconds of being launched.
Answer:
(a) The projectile takes approximately 4.420 seconds to reach the water, (b) The horizontal scope of the projectile is 1591.2 meters, (c) The remaining height to descend after 2 seconds of being launched is 63.624 meters.
Explanation:
The projectile experiments a parabolic motion, where horizontal speed remains constant and accelerates vertically due to the gravity effect. Let consider that drag can be neglected, so that kinematic equation are described below:
[tex]x = x_{o}+v_{o,x} \cdot t[/tex]
[tex]y = y_{o} + v_{o,y}\cdot t +\frac{1}{2}\cdot g \cdot t^{2}[/tex]
Where:
[tex]x_{o}[/tex], [tex]y_{o}[/tex] - Initial horizontal and vertical position of the projectile, measured in meters.
[tex]v_{o,x}[/tex], [tex]v_{o,y}[/tex] - Initial horizontal and vertical speed of the projectile, measured in meters per second.
[tex]t[/tex] - Time, measured in seconds.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]x[/tex], [tex]y[/tex] - Current horizontal and vertical position of the projectile, measured in meters.
Given that [tex]x_{o} = 0\,m[/tex], [tex]y_{o} = 80\,m[/tex], [tex]v_{o,x} = 360\,\frac{m}{s}[/tex], [tex]v_{o,y} = 0\,\frac{m}{s}[/tex] and [tex]g = -9.807\,\frac{m}{s^{2}}[/tex], the kinematic equations are, respectively:
[tex]x = 360\cdot t[/tex]
[tex]y = 80-4.094\cdot t^{2}[/tex]
(a) If [tex]y = 0\,m[/tex], the time taken for the projectile to reach the water is:
[tex]80 - 4.094\cdot t^{2} = 0[/tex]
[tex]t = \sqrt{\frac{80}{4.094} }\,s[/tex]
[tex]t \approx 4.420\,s[/tex]
The projectile takes approximately 4.420 seconds to reach the water.
(b) The horizontal scope is the horizontal distance done by the projectile before reaching the water. If [tex]t \approx 4.420\,s[/tex], the horizontal scope of the projectile is:
[tex]x = 360\cdot (4.420)[/tex]
[tex]x = 1591.2\,m[/tex]
The horizontal scope of the projectile is 1591.2 meters.
(c) If [tex]t = 2\,s[/tex], the height that remains to descend is:
[tex]y = 80-4.094\cdot (2)^{2}[/tex]
[tex]y = 63.624\,m[/tex]
The remaining height to descend after 2 seconds of being launched is 63.624 meters.
What must be the tension of a string 202 cm long and 3 x 10-2 Kg / m per unit length (µ) for it to emit a sound of 78 Hz?
Answer:
2980 N
Explanation:
The fundamental frequency of a string is:
f₁ = √(T/µ) / (2L)
78 Hz = √(T / (0.03 kg/m)) / (2 (2.02 m))
315.12 m/s = √(T / (0.03 kg/m))
99,300 m²/s² = T / (0.03 kg/m)
T = 2980 N
In your own words, discuss how energy conservation applies to a pendulum.
.
Where is the potential energy the most?
Where is the potential energy the least?
• Where is kinetic energy the most?
• Where is kinetic energy the least?
Answer:
when x=0 kinetic energy is maximum and potential energy is high
when it is in mean position the potential energy is maximum and vise versa
Explanation:
And x=0 when the pendulum is at highest point when moving like velocity become zero when ball reached highest point
mean position is the point when pendulum comes back to original position
I hope u understand
2. A solid sphere and a solid cylinder, both uniform and of the same mass and radius, roll without slipping at the same forward speed. It is correct to say that the total kinetic energy of the solid sphere is A) more than the total kinetic energy of the cylinder. B) less than the total kinetic energy of the cylinder. C) equal to the total kinetic energy of the cylinder.
PLEASE HELP. i will mark brainliest. and do more!
I would suggest an easier route. So for example, I would research light energy, where it comes from, and what causes it. I won't be able to do the work for you though.
Two trains run in the opposite direction with speeds of v1 = 15 m / s and v2 = 20 m / s. A passenger on the first train (the one on v1) notes that train 2 takes 6 s to pass on its side. What is the length of the second train? (The passenger is supposed to be immobile looking through the window)
Answer:
210 m
Explanation:
The speed of train 2 relative to train 1 is 15 m/s + 20 m/s = 35 m/s.
It takes 6 seconds for the train to pass, so the length of the train is:
(35 m/s) (6 s) = 210 m
Explain the method to measure the external diameter of a sphere
Answer:
Sphere is a geometrical object in dimensional space that surface of a circle and ball.
Explanation:
Sphere is that the circular objects in the two dimensional space (1) circle
(2) disk. Two dimensional space is a set of points and the distance of that point,The two points of Sphere that length and center.
Sphere can constructed as the named of surface form circle about any diameter. circle is the special type of the revolution replacing the circle,
sphere is the distance r is the radius of the ball and circle is the center of mathematical ball,as the center and the radius of the sphere is to respectively.
The ball and sphere has not be maintained mathematical references as a solid references. A sphere of any radius is centered at the number of zero.
define the unit of current
Answer:
The unit of current is defined as the flow of 1 coulomb of charge in one second
In this video, we see that a _____ magnetic field can create an electric current. In this video, we see that a _____ magnetic field can create an electric current. Changing Perpendicular Strong Dipole
Answer:
The correct option is (a) "Changing".
Explanation:
If a coil is placed in the magnetic field, due to the change in its magnetic flux an emf will induce in it. EMF is like voltage. So, due to the induced emf and current is induced in it. Hence, we can say that changing the magnetic field can create an electric current.
A 0.675 kg mass is attached to a
spring of spring constant 72.4 N/m,
pulled, and released. What is the
period of the resulting oscillation?
(Unit = s)
Answer:
T= 0.6 secExplanation:
This problem bothers on the simple harmonic motion of a loaded spring
Given data
mass attached, m= 0-.675 kg
spring constant, k= 72.4 N/m
the period of oscillation can be solved for using the formula bellow
[tex]T= 2\pi \sqrt{\frac{m}{k} }[/tex]
Substituting the given data into the expression above we have
[tex]T= 2*3.142\sqrt{\frac{0.675}{72.4} }\\T= 6.284*\sqrt{0.0093 }\\T= 0.6[/tex]
T= 0.6 sec
Answer:
0.607
Explanation:
Trust me
In a Little League baseball game, the 145 g ball reaches the batter with a speed of 15.0 m/s. The batter hits the ball, and it leaves his bat with a speed of 20.0 m/s in exactly the opposite direction. What is the magnitude of the impulse delivered by the bat to the ball
Answer: 5.075Ns
Explanation:
Given the following :
Mass of ball = 145g
Initial Speed of ball = 15m/s
Final speed of ball when hit by the batter = - 20m/s ( Opposite direction)
The impulse of a body is represented using the relation:
Force(f) * time(t) = mass (m) * (final Velocity(V) - initial velocity(u))
Therefore, using:
m(v - u) = impulse
Mass of ball = 145 / 1000 = 0.145kg
Impulse = 0.145(- 20 - 15)
Impulse = 0.145(-35)
Impulse = 5.075Ns
Which statement best describes the difference between how lenses and
mirrors interact with light?
A. Lenses bring light to a point; mirrors do not.
B. Lenses form images by reflecting light; mirrors do not.
C. Lenses spread light apart; mirrors do not.
D. Lenses form images by refracting light; mirrors do not.
Answer:D
Explanation:
Apex
Diagram 7 shows the velocity-time graph of an
object for 12 s.
When is the object at a distance of one-quarter of
the total distance travelled in the 12 s?
A 3 s
B 4 s
C 5 s
D 6 s
*The answer is D but can anyone tell me the solving steps? Or perhaps the answer is wrong?*
Answer:
t = 6
Explanation:
Displacement is equal to the area under a velocity vs time graph.
In this case, the area is a triangle. At time t, the base of the triangle is t. The height of the triangle can be found with similar triangles:
h / t = 8 / 12
h = ⅔ t
So the distance traveled at time t is:
d = ½ (t) (⅔ t)
d = ⅓ t²
The distance traveled at time 12 is:
D = ½ (12) (8)
D = 48
We want to find when d = D/4.
d = D/4
⅓ t² = 48/4
⅓ t² = 12
t² = 36
t = 6
Alternatively, since the acceleration is constant here, we could use a constant acceleration equation.
Δx = v₀ t + ½ at²
Given v₀ = 0 m/s and a = ⅔ m/s²:
Δx = (0) t + ½ (⅔) t²
Δx = ⅓ t²
When t = 12, Δx = 48.
⅓ t² = 48/4
t = 6
A 500 kg car starts with a force of 1000 N
1) Calculate the acceleration with which the car starts.
2) Determine the speed of the car 15 seconds after starting if we know what part of the rest
Answer:
2 m/s²
30 m/s
Explanation:
1) F = ma
1000 N = (500 kg) a
a = 2 m/s²
2) Given:
v₀ = 0 m/s
a = 2 m/s²
t = 15 s
Find: v
v = at + v₀
v = (2 m/s²) (15 s) + 0 m/s
v = 30 m/s
how to find volume of a cuboid in cm3
Answer:
we have to use formula of volume to find volume of a cuboid. ( i.e v = l ×b ×h)
Explanation:
here, let your length of cuboid be x cm, breadth be y cm and height be z cm .
now, formula to find volume of cuboid = length ×
breadth × height.
so, v( volume)= l (length)× b (breadth)× h (height)
or, v= x cm × y cm × z cm
therefore, volume is xyz cm^3..... answer.
hope it helps..
Answer: length times width times height
Explanation:
A vertical bar consists of three prismatic segments A1, A2, and A3 with cross-sectional areas of 6000 mm2 , 5000 mm2 , and 4000 mm2 , respectively. The bar is made of steel with E 5 200 GPa. Calculate the displacements at points B, D
Answer and Explanation:
For computing the displacement at point B and D we need to determine the following calculations
[tex]P_Net = P_C + P_E + P_B[/tex]
= 250 + 350 - 50
= 550 N
Now the deflection for bar AB is
[tex]\delta_{AB} = \frac{PL_{AB}}{AE} \\\\ = \frac{550 \times 500}{6,000 \times 200 \times 10^{3}}[/tex]
[tex]= 2.292 \times 10^{-4} mm[/tex]Now for bar BC it is
[tex]\delta_{BC} = \frac{PL_{BC}}{AE} \\\\ = \frac{(550 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 1.5 \times 10^{-04} mm[/tex]
And for bar CD it is
[tex]\delta_{CD} = \frac{PL_{CD}}{AE} \\\\ = \frac{(550 -250 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 0.875 \times 10^{-4} mm[/tex]
Now the displacement is as follows
For B
2.292 × 10^{-4} mm
For D, it is
[tex]= 2.292 \times 10^{-4} + 1.5 \times 10^{-4} + 0.875 \times 10^{-4} mm \\\\ = 4.667 \times 10^{-4} mm[/tex]
We simply applied the above formulas for determining the displacements at points B, D and the same is to be considered
A uniform metre rod of 5 metre length is suspended horizontally by two strings P and Q.Pis attached 0.8 metre from one end and Q is attached 2 metre from the other end.Given that the weight of the rod is 110N. Calculate the tension in each string
Answer:
The tension in string P is 25 N, while that of Q is 85 N.
Explanation:
Considering the conditions for equilibrium,
i. Total upward force = Total downward force
[tex]T_{P}[/tex] + [tex]T_{Q}[/tex] = 110 N
ii. Taking moment about P,
clockwise moment = anticlockwise moment
110 × (2.5 - 0.8) = [tex]T_{Q}[/tex] × (3 - 0.8)
110 × 1.7 = [tex]T_{Q}[/tex] × 2.2
187 = 2.2[tex]T_{Q}[/tex]
[tex]T_{Q}[/tex] = [tex]\frac{187}{2.2}[/tex]
[tex]T_{Q}[/tex] = 85 N
From the first condition,
[tex]T_{P}[/tex] + [tex]T_{Q}[/tex] = 110 N
[tex]T_{P}[/tex] + 85 N = 110 N
[tex]T_{P}[/tex] = 110 - 85
[tex]T_{P}[/tex] 25 N
Therefore, the tension in string P is 25 N while that of Q is 85 N.
A 6.0-μF capacitor charged to 50 V and a 4.0-μF capacitor charged to 34 V are connected to each other, with the two positive plates connected and the two negative plates connected. What is the total energy stored in the 6.0-μF capacitor at equilibrium?
Answer:
5702.88 J or 5.7mJ
Explanation:
Given that :
C 1 = 6.0-μF
C 2 = 4.0-μF
V 1 = 50V
V 2 = 34V
Note that : Q = CV
Q 1 = C1 * V1
Q 1 = 50×6 = 300μC
Q 2 = 34×4 = 136μC
Parallel connection = C 1 + C 2
= 6+4 = 10μC
V = Qt/C
Where Qt = Q1+Q2
V = Q1+Q2/C
V = 300+136/10
V = 437/10
V = 43.6volts
Uc1 = 1/2×C1V^2
= 1/2 × 6μF × 43.6^2
= 1/2 × 6μF × 1900.96
= 3μF × 1900.96volts
= 5702.88J
= 5702.88J/1000
= 5.7mJ
explain relative velocity.
Answer:
The relative velocity of an object A with respect to another object B.
Explanation:
The relative velocity of an object A with respect to another object B is the velocity that object A would appear to have to an observer situated on object B moving along with it.
Janaki Temple and Pashupatinath Temple are increasing our pride how
Answer:
Janaki temple and Pashupatinath Temple are found in Nepal. These structures are religious and they increase the pride of the country through tourism. These temples are important in the country and are mostly visited by tourists.
This also helps to bring in income for the country and also helps by attracting many visitors and a corresponding development of its tourism industry.
hey help me plzzzzz i will mark brainliest
Answer:
The answer to your question is given below.
Explanation:
Mechanical advantage (MA) = Load (L)/Effort (E)
MA = L/E
Velocity ratio (VR) = Distance moved by load (l) / Distance moved by effort (e)
VR = l/e
Efficiency = work done by machine (Wd) /work put into the machine (Wp) x 100
Efficiency = Wd/Wp x100
Recall:
Work = Force x distance
Therefore,
Work done by machine (wd) = load (L) x distance (l)
Wd = L x l
Work put into the machine (Wp) = effort (E) x distance (e)
Wp = E x e
Note: the load and effort are measured in Newton (N), while the distance is measured in metre (m)
Efficiency = Wd/Wp x100
Efficiency = (L x l) / (E x e) x 100
Rearrange
Efficiency = L/E ÷ l/e x 100
But:
MA = L/E
VR = l/e
Therefore,
Efficiency = L/E ÷ l/e x 100
Efficiency = MA ÷ VR x 100
Efficiency = MA / VR x 100
How much heat is required to convert 500g of liquid water at 28°C into steam at 150 °C? Take the specific heat capacity of water to be 4183 J/Kg °C and the latent heat of vaporization to be 2.26 × 10^6 J/Kg.
Answer:
Q = 1.404 × 10^(5) KJ
Explanation:
We are given:
Mass;m = 500 g = 0.5kg
Temperature 1;T1 = 28 °C
Temperature:T2 = 150 °C
Specific heat capacity;c_p = 4183 J/Kg °C
Latent heat of vaporization;L = 2.26 × 10^(6) J/Kg.
The heat energy needed is given by;
Q = sensible heat energy + Latent heat
Formula for sensible heat is;
Sensible heat energy = mc(t2 - t1)
Formula for Latent heat is ;
Latent heat = mL
Thus:
Q = mc(t2 - t1) + mL
Q = m[c(t2 - t1) + L]
Q = 0.5((4183(159 - 28) + (2.26 × 10^(6)))
Q = 1.404 × 10^(8) J = 1.404 × 10^(5) KJ
An object weighs 0.250 kgf in air, 0.150 kgf in water and 0.125 kgf in an oil.
Find out the density of the object and the oil.
Answer: Upthrust = Weight - Apparent weight
= 0.250 kgf - 0. 150 kgf
= 0.100 kgf
Density = mass / volume
volume = mass / density
= 0.100 kg / (1000 kg / m³)
= 0.0001 m³
density of object = mass / volume
= 0.250 kg / 0.0001 m³
= 2500 kg / m³
upthrust of oil = Weight - Apparent weight
= 0.250 kgf - 0.125 kgf
= 0.125 kgf
density = mass / volume
= 0.125 kg / 0.0001 m³
= 1250 kg/m³
density of the object = 2500 kg / m³
density of oil = 1250 kg / m³
you (60 kg) are standing in a (500 kg) elevator that is moving upwards from a ground floor on a building what is the power rating of the motor that can lift this elevator if the elevator travels a distance of 20m upwards in 15 s
Explanation:
Power = work / time
Power = force × distance / time
P = (650 kg) (10 m/s²) (20 m) / (15 s)
P = 8667 W
ride and average of 15mph for 30 miles, how long does it take?
Answer:
2 hrs
Explanation:
time = distance ÷ speed
We have seen that starlight passing through the interstellar medium is dimmed and reddened. Look at the photo of a sunset on Earth. The Sun’s light also appears reddish at sunset. Given your understanding of the reddening of starlight, why do you think sunsets appear red?
Answer:
Explanation:
Reddening of sun's rays at sunset and sunrise is due to scattering of light . The white light consisting of seven colours coming from the sun are scattered in different directions when they fall on the air particles present in atmosphere . Red coloured light scatters least and it travels straight forward to the viewer on the earth . On the other hand other colours scatter most and therefore they go out of area of vision for the viewer on the earth . Since only red colour reaches the eye of the viewer , sun's ray appear red . This happens during sunrise and sunset . It is so because during this period , sun rays travel far greater distance through atmosphere , so scattering is most pronounced .
Find the mass. 10 points. Will give brainliest.
Answer:
3.94 kgExplanation:
Given,
Force ( f ) = 30 N
Acceleration(a) = 7.6 m/s
Now, Let's find the mass of the ball
Using the Newton's second law of motion:
We get:
[tex]force \: = mass \: \times acceleration[/tex]
plug the value
[tex]30 \: = m \: \times 7.6[/tex]
Use the commutative property to reorder the terms
[tex] 30 = 7.6 \: m[/tex]
Swap the sides of the equation
[tex]7.6m = 30[/tex]
Divide both sides of the equation by 7.6
[tex] \frac{7.6 \: m}{7.6} = \frac{30}{7.6} [/tex]
Calculate
[tex]m = 3.94 \: kg[/tex]
Hope this helps..
Best regards!!
Answer:
[tex]\displaystyle \boxed{\mathrm{3.95 \: kg }}[/tex]
Explanation:
[tex]\mathrm{force \: (N) = mass \: (kg) \times acceleration \: (m/s^2)}[/tex]
[tex]\mathrm{force = 30N}[/tex]
[tex]\mathrm{acceleration = 7.6 \: m/s^2 }[/tex]
[tex]\mathrm{Find \: the \: mass.}[/tex]
[tex]\mathrm{30 = m \times 7.6}[/tex]
[tex]\displaystyle \mathrm{m =\frac{30}{7.6} }[/tex]
[tex]\displaystyle \mathrm{m = 3.947... }[/tex]
A catapult is usedto fire an object into the air describe the energy transfers when the catapult is released and stretched
Explanation:
potential energy ===> kinetic energy
when an object is stretched there will be a stored energy in it enough to react to the upcoming change
that is the potential energy
similar to a stretched elastic band
kinetic energy is the energy on a moving object
*If a kinetic energy takes place there must gave been a potential energy before*
A catapult is used to fire an object into the air, the potential energy transfers as the elastic potential energy and to the kinetic energy when the catapult is released and stretched.
What is the energy conversion taken place in Catapult?The potential energy is associated with bodies that are above a reference point, at that reference point the value of potential energy is taken as zero. For example, if an object with a mass M is in a tower that is 140 meters high, its potential energy is defined as the product of the mass of the object by gravity and by the height at which the object is measured from the reference point.
Ep =mgh
When talking about elastic objects such as springs or elastic fibers, it is usually understood that there is an elastic potential energy associated with the constant of the spring. This can be calculated using the following equation:
U ela = 1/2×k×(Dx)²
where:
k = elastic constant of the elastic material [N/m]
Dx = distance stretched or compressed of the elastic material [m]
U = elastic energy [Joules]
So, there are difference between the elastic potential energy and the potential energy.
In a catapult, Initially, energy is stored in the form of potential energy which is later converted into kinetic energy. Potential energy can be stored in the form of elastic potential energy in the case of elastic. It suddenly releases the energy to propel the object into the air.
Learn more about catapult,
https://brainly.com/question/20899342
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Ionic compounds _____.
Explanation:
Are the compounds formed by the ionic bonding or electronic bonding. They are formed by transferring the electron form one element's valance shell to other element's shell.
i hope it helps...
HELP me pleaseeee somebody
an object is placed 30cm from a mirror of focal length 15 cm the object is 7.5cm tall. where is the image located? how tall is the image??
Explanation:
It is given that,
Object distance from the mirror, u = -30 cm
Focal length of the mirror, f = +15 cm
Size of the object, h = 7.5 cm
We need to find the image distance and the size of the image.
Mirror's formula, [tex]\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}[/tex]
v is image distance
[tex]\dfrac{1}{v}=\dfrac{1}{f}-\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{(15)}-\dfrac{1}{(-30)}\\\\v=10\ cm[/tex]
Let h' is the size of the image. So,
[tex]\dfrac{h'}{h}=\dfrac{-v}{u}\\\\h'=\dfrac{-vh}{u}\\\\h'=\dfrac{-10\times 7.5}{-30}\\\\h'=2.5\ cm[/tex]
So, the image is located at a distance of 10 cm and the size of the image is 2.5 cm.