Fragen 202
Antworten 16


Here's another way to solve this problem, focusing on proportionality within the parallelogram:


Proportions in Similar Triangles:


Since ABCD is a parallelogram, lines AD and BC are parallel. When line DE intersects line BC at point F, it creates two transversal lines. Because of this, corresponding angles on alternate sides of DE are congruent (alternate interior angles)


Therefore, triangles EAD and EBF are similar by Angle-Angle Similarity (AA).


Since the triangles are similar, the ratio of their areas is equal to the square of the ratio of their corresponding side lengths:


Area(EBF) / Area(EAD) = (length(BF) / length(AD))^2


Given Information:


We are given that the area of triangle EBF is 4 and the area of triangle EAD is 9. Plugging these values into the equation:


4 / 9 = (length(BF) / length(AD))^2


Proportionality in a Parallelogram:


In a parallelogram, opposite sides have the same length. Therefore, length(BF) = length(AE) and length(AD) = length(BC). Substituting these equalities into the equation from step 2:


4 / 9 = (length(AE) / length(BC))^2


Area of Parallelogram:


The area of a parallelogram is equal to the base times the height. Since AD is parallel to BC, the height of parallelogram ABCD is the same as the height of triangle EAD (considering side AE as the base). We can express this using proportionality:


Area(ABCD) ∝ length(BC) * height(EAD)


From step 3, we know the ratio between the base of triangle EAD (which is also a base of the parallelogram) and side BC of the parallelogram:

length(AE) / length(BC) = √(4/9) (taking the square root of both sides)


Combining Proportions:


Since the area of the parallelogram is proportional to the product of its base and height, and we know the ratio between the base and a side of the parallelogram, we can combine these proportions:


Area(ABCD) ∝ (√(4/9)) * height(EAD)


Note: We don't need to find the actual height of triangle EAD since it cancels out when solving for the relative area of the parallelogram.


Relative Area of Parallelogram:


Since the area of triangle EAD is a constant value (9) and the other factor in the proportion is a constant resulting from the given information, the area of parallelogram ABCD is also proportional to a constant value.


Therefore, relative to the area of triangle EAD, the area of parallelogram ABCD is:


Area(ABCD) ∝ √(4/9) * Area(EAD) = √(4/9) * 9 = 4


Scaling to Actual Area:


While the previous step gives us the relative area compared to triangle EAD, we can find the actual area by considering that the area of triangle EBF is given as 4.


Since triangles EAD and EBF are similar, the ratio of their areas is the square of the ratio of their corresponding side lengths (as established in step 1). Therefore, the area of triangle EAD is 4 times the area of triangle EBF:


Area(EAD) = 4 * Area(EBF) = 4 * 4 = 16


Now, we can use the relative area we found in step 6 to solve for the actual area of the parallelogram:


Area(ABCD) = √(4/9) * Area(EAD) = √(4/9) * 16


Area(ABCD) = 4 * 4 = 16​.


Here's how to estimate the lifetime of the sun based on the given information:


Energy from Hydrogen Fusion:


Every time two hydrogen atoms fuse, they release 2.3 × 10^-13 J of energy.


Mass of Converted Hydrogen:


To find the total mass of hydrogen converted per second to generate the sun's power output, we can divide the power (energy per second) by the energy released per fusion:


Mass of converted hydrogen per second (m_h_converted) = Sun's power / Energy per fusion


m_h_converted = (3.6 × 10^26 J/s) / (2.3 × 10^-13 J/fusion)


m_h_converted ≈ 1.57 × 10^39 kg/s (This is the mass of hydrogen converted to helium every second)


Mass of Fused Hydrogen Over Time:


We are estimating the lifetime (t) of the sun. To find the total mass of hydrogen converted over that time, we multiply the mass converted per second by the lifetime:


Total mass of converted hydrogen (M_h_converted) = m_h_converted * t


Relating Converted Hydrogen to Initial Mass:


We know the initial mass of the sun (m_sun) is 2 × 10^30 kg. Since we assumed the sun started as pure hydrogen, this initial mass represents the total amount of hydrogen available for fusion.


Not all the mass of the hydrogen atom is converted to energy during fusion. A small amount is converted to helium, which has a slightly higher mass.


To account for this, we can introduce a factor (f) representing the fraction of the hydrogen mass that gets converted to energy. This factor is less than 1 (around 0.007).


M_h_converted = f * m_sun


Solving for Lifetime:


Now we can equate the total mass of converted hydrogen over time (from step 3) to the initial mass of the sun (adjusted for conversion efficiency) from step 4:


m_h_converted * t = f * m_sun


(1.57 × 10^39 kg/s) * t = f * (2 × 10^30 kg)


t = (f * 2 × 10^30 kg) / (1.57 × 10^39 kg/s)


Finding the Lifetime:




f = 0.01 (1% conversion):




Converting Seconds to Years:


There are 31,536,000 seconds in a year. Converting the estimated lifetimes:


For f = 0.01: Lifetime ≈ 1.27 × 10^11 seconds / (31,536,000 seconds/year) ≈ 4.03 × 10^3 years (around 4,000 years)


Absolutely, based on the formula and the constants provided, we can calculate the value of Planck's constant (h) from the experimental data.


Here's how:


Identify the Given Values:


f_peak (peak frequency): This value likely comes from your experiment and needs to be plugged in. We'll denote it as an unknown for now.


k_B (Boltzmann's constant): k_B ≈ 1.38 × 10^-23 m² kg s⁻² K⁻¹ (given)


T (temperature): This value likely comes from your experiment and needs to be plugged in. We'll denote it as an unknown for now.


Rearrange the Formula for h:


We want to isolate h on one side of the equation. The formula is:


f_peak = 2.821 * (k_B * T) / h


To solve for h, multiply both sides by h and divide both sides by 2.821 * k_B * T:


h = (f_peak * 2.821 * k_B * T) / (f_peak)


We can simplify this further since f_peak appears in both the numerator and denominator and cancels out:


h = 2.821 * k_B * T


Plug in Experimental Data:


Now, replace f_peak and T with the actual values you obtained from your experiment. Make sure the units are consistent.


h = 2.821 * (1.38 × 10^-23 m² kg s⁻² K⁻¹) * T (in Kelvin)


Note: Since k_B is a very small number, the final value of h will depend significantly on the measured values of f_peak and T.




Let's say your experiment measured a peak frequency of f_peak = 5.00 x 10^14 Hz (hertz) and the temperature of the black body was T = 6000 Kelvin.


h = 2.821 * (1.38 × 10^-23 m² kg s⁻² K⁻¹) * 6000 K


h ≈ 6.61 x 10^-34 J s (joules per second)


This is a typical range for the value of Planck's constant.