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:
No.
Explanation:
The spare tire is also moving at the speed of the jeep. When it separates from the jeep, both will be moving at the same horizontal speed, only that the spare tire will also fall at the same time. This if we neglect air friction, that could be a problem since it could cancel the horizontal velocity of the spare tire, although the jeep is blocking most of the air for the spare tire to feel any significant effect in such a short time.
Answer:
0.005 m
Explanation:
length of steel (L°) = 12 m
initial temperature (T) = 16 degrees
expected temperature (T') = 50 degrees
We can find how large the gaps should be if the track is not to buckle when the temperature is as high as 50 degrees from the formula below
ΔL = ∝L°ΔT where
- ΔL = expansion / gap
- ∝ = linear expansion coefficient of steel =

- L° = initial length
- ΔT = change in temperature
ΔL =
x 12 x (50-16) = 0.005 m
Weather
Particles in air such as smoke smog