Answer:
![v_i = 18.86 m/s](https://tex.z-dn.net/?f=v_i%20%3D%2018.86%20m%2Fs)
Explanation:
As we know that the speed of the rocket is v1 and v2 at the bottom and top of the window
then we will have
![d = (\frac{v_1 + v_2}{2}) t](https://tex.z-dn.net/?f=d%20%3D%20%28%5Cfrac%7Bv_1%20%2B%20v_2%7D%7B2%7D%29%20t)
![2 = (\frac{v_1 + v_2}{2})(0.15)](https://tex.z-dn.net/?f=2%20%3D%20%28%5Cfrac%7Bv_1%20%2B%20v_2%7D%7B2%7D%29%280.15%29)
![26.67 m/s = v_1 + v_2](https://tex.z-dn.net/?f=26.67%20m%2Fs%20%3D%20v_1%20%2B%20v_2)
also we know that
![v_2 - v_1 = (-9.81)(t)](https://tex.z-dn.net/?f=v_2%20-%20v_1%20%3D%20%28-9.81%29%28t%29)
![v_2 - v_1 = (-9.81)(0.15) = -1.47](https://tex.z-dn.net/?f=v_2%20-%20v_1%20%3D%20%28-9.81%29%280.15%29%20%3D%20-1.47%20)
now we have
![v_2 = 12.6](https://tex.z-dn.net/?f=v_2%20%3D%2012.6%20)
also we have
![v_1 = 14.1 m/s](https://tex.z-dn.net/?f=v_1%20%3D%2014.1%20m%2Fs)
now if the sill of the window is at height 8 m from the ground then we have
![v_1^2 - v_i^2 = 2 a h](https://tex.z-dn.net/?f=v_1%5E2%20-%20v_i%5E2%20%3D%202%20a%20h)
![(14.1^2) - v_i^2 = 2(-9.81)(8)](https://tex.z-dn.net/?f=%2814.1%5E2%29%20-%20v_i%5E2%20%3D%202%28-9.81%29%288%29)
![v_i = 18.86 m/s](https://tex.z-dn.net/?f=v_i%20%3D%2018.86%20m%2Fs)
We know that speed is a scalar unit while velocity is a vector. The signs are mostly concerned with the magnitude that the car should travel in, the direction is not as important.
Hope I helped :)
Answer:
Guessing you just need help with the definition but if it's the question I can still help you.
<h3><u>Answer;</u></h3>
1 × 10^-8 M
<h3><u>Explanation</u>;</h3>
pH is given by the -log[H+] while
pOH is given by the -log[OH-]
But;
pH + pOH = 14
Thus; if pH is 6, then pOH = 8
pOH = 8
-log[OH-] = 8
[OH-] = 10^-8 M
The concentration of OH- ions at a pH of 6 is 1 × 10^-8 M
Newton’s first law is commonly stated as:
An object at rest stays at rest and an object in motion stays in motion.
However, this is missing an important element related to forces. We could expand it by stating:
An object at rest stays at rest and an object in motion stays in motion at a constant speed and direction unless acted upon by an unbalanced force.
By the time Newton came along, the prevailing theory of motion—formulated by Aristotle—was nearly two thousand years old. It stated that if an object is moving, some sort of force is required to keep it moving. Unless that moving thing is being pushed or pulled, it will simply slow down or stop. Right?
This, of course, is not true. In the absence of any forces, no force is required to keep an object moving. An object (such as a ball) tossed in the earth’s atmosphere slows down because of air resistance (a force). An object’s velocity will only remain constant in the absence of any forces or if the forces that act on it cancel each other out, i.e. the net force adds up to zero. This is often referred to as equilibrium. The falling ball will reach a terminal velocity (that stays constant) once the force of air resistance equals the force of gravity.
Hope this help