HI!
Conventional vehicles use gasoline or diesel to power an internal combustion engine. Hybrids also
use an internal combustion engine—and can be fueled like normal
cars—but have an electric motor and battery, and can be partially or
wholly powered by electricity. Also pollute less and save the drivers money.
Good Day.
Imagine you are in a swimming pool 30m deep. Assuming you know that water is denser than air, you would know that the 30m of water above you will carry more weight, and press down on your body. Say you were in a swimming pool 60m deep, you would be sandwiched between 30m of water pressing down on you, and the upthrust created by the 30m of water below you.
In a building 30m up, the pressure will be regulated, as you are in a building. The floor will be strong enough to support the weight of the body, and the body will not recoil into itself.
First we gotta use an equation of motion:
![d = ut + \frac{1}{2} a {t}^{2}](https://tex.z-dn.net/?f=d%20%3D%20ut%20%2B%20%5Cfrac%7B1%7D%7B2%7D%20a%20%7Bt%7D%5E%7B2%7D%20)
Our vertical distance d= 100 m, initial vertical speed u = 0 m/s (because velocity is fully horizontal), and vertical acceleration a = 9.8 m/s2 because of gravity. Let's plug it all in!
![100 = 0 + \frac{1}{2} (9.8) {t}^{2}](https://tex.z-dn.net/?f=100%20%3D%200%20%2B%20%5Cfrac%7B1%7D%7B2%7D%20%289.8%29%20%7Bt%7D%5E%7B2%7D%20)
Now we just need to solve for t:
![{t}^{2} = \frac{2(100)}{9.8} \\ \\ t = \sqrt{\frac{2(100)}{9.8}}](https://tex.z-dn.net/?f=%20%7Bt%7D%5E%7B2%7D%20%3D%20%5Cfrac%7B2%28100%29%7D%7B9.8%7D%20%5C%5C%20%5C%5C%20t%20%3D%20%5Csqrt%7B%5Cfrac%7B2%28100%29%7D%7B9.8%7D%7D%20)
Hit the calculators, and you'll get 4.5 seconds!
A trough is the lowest point in a wave.
Earth's gravity pulls air as close to the surface as possible. As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level.