Hey there
Crying is a signal <span>of distress to babies.</span>
Well, 0.1 is actually less than 0.7, but I understand what you're asking.
The coefficient of friction describes the relationship between two surfaces
that are sliding by each other. The higher the coefficient of friction is, the
'rougher' the meeting is, and the harder it is for one to slide over the other.
A skate blade against ice has a very low coefficient of friction. Sandpaper
against blue jeans has a high coefficient of friction.
A higher coefficient of friction means that when one thing is sliding over
the other one, friction robs more energy from the motion. It's harder to
push one thing over the other one, and when you let go, the moving one
slows down and stops sooner.
Air resistance is actually an example of friction. It prevents falling things
from falling as fast as they would if there were no air. The coefficient of
friction when something moves through air is pretty low. If the same
object were trying to move through molasses or honey, the coefficient
of friction would be greater.
Friction robs energy, and turns it into heat. So, especially in machinery with
moving parts, we want to make the coefficient of friction between the moving parts
as small as possible. That's what the OIL in a car's engine is for.
Density is a physical property that describes the relationship between mass and volume. Density is the amount of matter in a given space, or volume.
The correct response is B .
F=ma
a=F/m
F=+250N + (-130N)=120N LEFT
('m summing my forces because they are moving about the same axis, and the negative/positive accounts for the arbitrary directions I assign)
m=32kg
F=120N/32kg=3.75m/s^2 to the LEFT
3.75m/s^2 to the LEFT
