Answer:
58.27 N
Explanation:
the data we have is:
mass: 
coefficient of friction: 
and we also know the acceleration of gravity is 
We need to do an analysis of horizontal and vertical forces acting on the object:
-------
Vertically the forces acting on the object:
- Normal force
(acting up from the object)
- weight:
(acting down from)
so the sum of forces in the vertical axis "y" are:
from Newton's second Law we know that 
, so:
and since the object is not accelerating in the vertical direction (the movement is only horizontal) 
, and:
-----------
now let's analyze the horizontal forces
- frictional force:
and since 
--> 
- force to move the object:
and the two forces just mentioned must be opposite, thus the sum of forces in the "x" axis is:
and we are told that the crate moves at a steady speed, thus there is no acceleration: 
and we get:
substituting known values:
Answer:
D. The air we breathe is a homogeneous mixture because it has substances but the same appearance throughout.
Explanation:
The air we breathe is a homogeneous mixture.
Air is a mixture of many gases. A homogeneous mixture is one whose constituents exists in one phase.
Air is a gas - gas mixtures.
A mixture has indefinite composition. They consist of two or more elements and or compounds in any proportion by mass.
Constituents retain their identities i.e. physical properties are retained.
Answer:
D = 43 m
Explanation:
given,
initial velocity = 18 m/s
angle θ = 60°
total horizontal distance covered by the shell is
applying conservation of momentum in horizontal direction
m v₀ cos θ = m₁v₁ + m₂ v₂
m v₀ cos θ = 0.5 m v₂
v₂ = 2 v₀ cos θ.
distance covered by the shell from point of explosion
R' = v t
= 
=
= 
= R
total distance traveled by the shell is
D = 
= 1.5 R
= 
D = 
= 42.9 ≅ 43 m
D = 43 m
The wave will decrease in its frequency due to a disturbing force acting upon it.
Become more positive instead of negative
