Answer:
4.163 m
Explanation:
Since the length of the bridge is
L = 380 m
And the bridge consists of 2 spans, the initial length of each span is
![L_i = \frac{L}{2}=\frac{380}{2}=190 m](https://tex.z-dn.net/?f=L_i%20%3D%20%5Cfrac%7BL%7D%7B2%7D%3D%5Cfrac%7B380%7D%7B2%7D%3D190%20m)
Due to the increase in temperature, the length of each span increases according to:
![L_f = L_i(1+ \alpha \Delta T)](https://tex.z-dn.net/?f=L_f%20%3D%20L_i%281%2B%20%5Calpha%20%5CDelta%20T%29)
where
is the initial length of one span
is the temperature coefficient of thermal expansion
is the increase in temperature
Substituting,
![L_f=(190)(1+(1.2\cdot 10^{-5})(20))=190.0456 m](https://tex.z-dn.net/?f=L_f%3D%28190%29%281%2B%281.2%5Ccdot%2010%5E%7B-5%7D%29%2820%29%29%3D190.0456%20m)
By using Pythagorean's theorem, we can find by how much the height of each span rises due to this thermal expansion (in fact, the new length corresponds to the hypothenuse of a right triangle, in which the base is the original length of the spand, and the rise in heigth is the other side); so we find:
![h=\sqrt{L_f^2-L_i^2}=\sqrt{(190.0456)^2-(190)^2}=4.163 m](https://tex.z-dn.net/?f=h%3D%5Csqrt%7BL_f%5E2-L_i%5E2%7D%3D%5Csqrt%7B%28190.0456%29%5E2-%28190%29%5E2%7D%3D4.163%20m)
We could determine the acceleration using this formula
![\boxed{a= \dfrac{v_{1}-v_{0}}{t}}](https://tex.z-dn.net/?f=%5Cboxed%7Ba%3D%20%5Cdfrac%7Bv_%7B1%7D-v_%7B0%7D%7D%7Bt%7D%7D)
Joe accelerated from 35 m/s to 50 m/s in 50 seconds, plug in the numbers
a=
![\dfrac{v_{1}-v_{0}}{t}](https://tex.z-dn.net/?f=%5Cdfrac%7Bv_%7B1%7D-v_%7B0%7D%7D%7Bt%7D)
a =
![\dfrac{50-35}{50}](https://tex.z-dn.net/?f=%5Cdfrac%7B50-35%7D%7B50%7D)
a =
![\dfrac{15}{50}](https://tex.z-dn.net/?f=%5Cdfrac%7B15%7D%7B50%7D)
a = 0.3
The acceleration is 0.3 m/s²
Answer:
Ionic radius is greater than atomic radius in an anion.
Thus, astronomers can<span> identify what kinds of stuff are in </span>stars<span> from the lines they find in the </span>star's spectrum<span>. This type of study is called spectroscopy. The science of spectroscopy is quite sophisticated. ... The spectral line also </span>can tell<span> us about any magnetic field of the </span>star<span>.</span>