Answer:
<em>The coefficient of static friction between the crate and the floor is 0.41</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in the air or rough surfaces, it loses acceleration and velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
[1]
Where 
is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W = m.g
The crate of m=20 Kg has a weight of:
W = 20*9.8
W = 196 N
The normal force is also N=196 N
We can find the coefficient of static friction by solving [1] for :
The friction force is equal to the minimum force required to start moving the object on the floor, thus Fr=80 N and:
The coefficient of static friction between the crate and the floor is 0.41
Answer:
b) a = -k / m x
, c) d²x / dt² = - A w² cos (wt+Ф)
, d) and e) T = 2π √m / k
h) a = - A w² cos (wt+Ф)
Explanation:
a) see free body diagram in the attachment
b) We write Newton's second law
Fe = m a
-k x = ma
a = -k / m x
c) the acceleration is
a = d²x / dt²
If x = A cos wt
v = dx / dt = -A w sin (wt
+Ф)
a = d²x / dt² = - A w² cos (wt+Ф)
d) we substitute in Newton's second law
d²x / dt² = -k / m x
We call
w² = k / m
e) substitute to find w
-A w² cos (wt+Ф) = -k / m A cos (wt+Ф)
w² = k / m
Angular velocity and frequency are related
w = 2π f
f = 1 / T
We substitute
T = 2π / w
T = 2π √m / k
g) v= - A w sin (wt+Ф)
h) acceleration is
a = - A w² cos (wt+Ф)
The conversion steps listed above in order from start to finish are already in an arranged form from 1-4.
<h3>What is a biosphere?</h3>
A biosphere can be defined as the part of the earth that supports life. These include :
The flow of energy through the biosphere includes
- Energy from the sun which is as a result of the nuclear fusion,
- the energy released is absorbed by plant chlorophyll,
- Chemical energy is released during respiration.
- Photosynthesis converts carbon dioxide and water into glucose and oxygen.
Learn more about biosphere here:
brainly.com/question/12467010
#SPJ1
This question is checking to see whether you understand the meaning
of "displacement".
Displacement is a vector:
-- Its magnitude (size) is the distance between the start-point and
the end-point, no matter what route might have been followed along
the way.
-- Its direction is the direction from the start-point to the end-point.
Talking about the Earth's orbit around the sun, we can forget about
the direction of the displacement, and just talk about its magnitude
(size).
If we pretend that the sun is not moving and dragging the whole
solar system along with it, then what do we see the Earth doing
in one year ?
We mark the place where the Earth is at the stroke of midnight
on New Year's Eve. Then we watch it as it swings around through
this gigantic orbit, all the way around the sun, and in a year, it's back
to the same point that we marked !
So what's the magnitude of the displacement in exactly one year ?
It's the distance between the start-point and the end-point. But the
Earth came back to the same place it started from, so there's no
separation at all between the start-point and the end-point.
The Earth covered a huge distance in that year, but the displacement
is zero.
