The transit method requires watching the light output of a star over long periods of time. A transit occurs when the planet crosses in front of its star from earths point of view. Since there is a small object (the planet) now blocking some of the star, it appears to dim a little bit for a while until the planet passes. If we are in a position where that occurs regularly (most paths of planets do not happen to be on the line of sight between earth and their star) we can deduce the period of orbit. From the amount of dimming and the period you can estimate the mass
This is an example of inertia - the body keeps it's energy because there is no force applied to it. When we try to stop it's motion, it resists. A man is not rigidly attached to the bus, so he keeps moving forward, at least until he hits the front window from inside. Answer is D.
<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
Answer:
The change in momentum = -20000 kg m/s.
Explanation:
Mass m = 1000 kg
speed v₁ = 20 m/s
speed v₂ = 0 m/s
We know that,
The change in momentum
ΔP = m (Δv)
ΔP = m (v₂ - v₁)
= 1000 (0 - 20)
= 1000 (-20)
= -20000 kg m/s
Thus, the change in momentum = -20000 kg m/s.
Note: negative sign indicates that the velocity is reducing when it hits the barrier.
Ethylene glycol is termed as the primary ingredients in antifreeze.
The ethylene glycol molecular formula is C₂H₆O₂.
Molar mass of C₂H₆O₂ is = (2×12) +(6×1) + (216) = 62g/mol
Now that antifreeze by mass is 50%, then there is 1kg of ethylene glycol which is present in 1kg of water.
ΔTf = Kf×m
ΔTf = depression in the freezing point.
= freezing point of water freezing point of the solution
= O°c - Tf
= -Tf
Kf = depression in freezing constant of water = 1.86°C/m
M is the molarity of the solution.
=(mass/molar mass) mass of solvent in kg
=1000g/62 (g/mol) /1kg
=16.13m
If we plug the value we get
-Tf = 1.86 × 16.13 = 30
Tf = -30°c
