Answer:![3.874 m/s^2](https://tex.z-dn.net/?f=3.874%20m%2Fs%5E2)
Explanation:
Given
Car speed decreases at a constant rate from 64 mi/h to 30 mi/h
in 3 sec
![60mi/h \approx 26.8224m/s](https://tex.z-dn.net/?f=60mi%2Fh%20%5Capprox%2026.8224m%2Fs)
![34mi/h \approx 15.1994 m/s](https://tex.z-dn.net/?f=34mi%2Fh%20%5Capprox%2015.1994%20m%2Fs)
we know acceleration is given by ![=\frac{velocity}{Time}](https://tex.z-dn.net/?f=%3D%5Cfrac%7Bvelocity%7D%7BTime%7D)
![a=\frac{15.1994-26.8224}{3}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B15.1994-26.8224%7D%7B3%7D)
![a=-3.874 m/s^2](https://tex.z-dn.net/?f=a%3D-3.874%20m%2Fs%5E2)
negative indicates that it is stopping the car
Distance traveled
![v^2-u^2=2as](https://tex.z-dn.net/?f=v%5E2-u%5E2%3D2as)
![\left ( 15.1994\right )^2-\left ( 26.8224\right )^2=2\left ( -3.874\right )s](https://tex.z-dn.net/?f=%5Cleft%20%28%2015.1994%5Cright%20%29%5E2-%5Cleft%20%28%2026.8224%5Cright%20%29%5E2%3D2%5Cleft%20%28%20-3.874%5Cright%20%29s)
![s=\frac{488.419}{2\times 3.874}](https://tex.z-dn.net/?f=s%3D%5Cfrac%7B488.419%7D%7B2%5Ctimes%203.874%7D)
s=63.038 m
<span>
</span><span>Waves on a pond are an example of which kind of wave?
</span>B. surface waves
Answer:
Explanation 118 = (1/2) * 0.15 * v² 118 = 0.075 * v² v² = 1573.33 m/s ... since KE = m/2*V^2 , then : V = √2KE/m = √20*118/1.5 = 39.67 m//sec ( 142.8 km/h ; 88.75 mph).:
If the car moves along the distance it will be 16 of the line graph where is independent of the graph
Answer:
![v=\sqrt{\frac{gR_E}{2}}](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cfrac%7BgR_E%7D%7B2%7D%7D)
Explanation:
Satellites experiment a force given by Newton's Gravitation Law:
![F=\frac{GMm}{r^2}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7BGMm%7D%7Br%5E2%7D)
where M is Earth's mass, m the satellite's mass, r the distance between their gravitational centers and G the gravitational constant.
We also know from Newton's 2nd Law that <em>F=ma, </em>so putting both together we will have:
![ma=\frac{GMm}{r^2}](https://tex.z-dn.net/?f=ma%3D%5Cfrac%7BGMm%7D%7Br%5E2%7D)
![a=\frac{GM}{r^2}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7BGM%7D%7Br%5E2%7D)
If we are on the surface of the Earth, the acceleration would be g and
(Earth's radius):
![g=\frac{GM}{R_E^2}](https://tex.z-dn.net/?f=g%3D%5Cfrac%7BGM%7D%7BR_E%5E2%7D)
Which we will write as:
![gR_E^2=GM](https://tex.z-dn.net/?f=gR_E%5E2%3DGM)
If we are on orbit the acceleration is centripetal (
), so we have:
![\frac{v^2}{r}=a=\frac{GM}{r^2}=\frac{gR_E^2}{r^2}](https://tex.z-dn.net/?f=%5Cfrac%7Bv%5E2%7D%7Br%7D%3Da%3D%5Cfrac%7BGM%7D%7Br%5E2%7D%3D%5Cfrac%7BgR_E%5E2%7D%7Br%5E2%7D)
![v^2=\frac{gR_E^2}{r}](https://tex.z-dn.net/?f=v%5E2%3D%5Cfrac%7BgR_E%5E2%7D%7Br%7D)
![v=\sqrt{\frac{gR_E^2}{r}}](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cfrac%7BgR_E%5E2%7D%7Br%7D%7D)
And if this orbit has a radius
we have:
![v=\sqrt{\frac{gR_E^2}{2R_E}}=\sqrt{\frac{gR_E}{2}}](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cfrac%7BgR_E%5E2%7D%7B2R_E%7D%7D%3D%5Csqrt%7B%5Cfrac%7BgR_E%7D%7B2%7D%7D)