The correct choice is Buffers.
Buffers contains both acids and bases in equilibrium.when base is added to buffers, they adjust the pH value by releasing hydrogen ions.when acid is added to buffers, they adjust the pH value by consuming hydrogen ions. hence these substances resist any change in their pH value by releasing or absorbing hydrogen ions.This process keeps the pH value constant.
Kinetic Energy,K.E=1/2MV²
mass,m=16kg
velocity,v=4m/s
K.E=1/2×16×4²
=128kgm²/s²
=128 Joules
Answer:
Time taken, 
Explanation:
It is given that, a small metal ball is suspended from the ceiling by a thread of negligible mass. The ball is then set in motion in a horizontal circle so that the thread’s trajectory describes a cone as shown in attached figure.
From the figure,
The sum of forces in y direction is :


Sum of forces in x direction,

.............(1)
Also, 
Equation (1) becomes :

...............(2)
Let t is the time taken for the ball to rotate once around the axis. It is given by :

Put the value of T from equation (2) to the above expression:


On solving above equation :

Hence, this is the required solution.
<span>At the exact instant the blue ball reaches maximum height, it is stationary for that millisecond in time before it begins to fall, therefore its speed is zero. (The other factors listed have no effect on the speed at the moment of maximum height.)</span>
Well, I'm not sure right now that it actually does.
But if it does, that's because the sun is about 400 times
FARTHER from the Earth than the moon is.