Geologists use the Mohs Harness Scale (aka the Scratch Test) to determine the hardness of a mineral.
For more info, check out http://geology.com/minerals/mohs-hardness-scale.shtml
Answer:
P = 1471500 [Pa]
Explanation:
We must remember that pressure is defined as the relationship between Force over the area.
where:
P = pressure [Pa] (units of pascals)
F = force [N] (units of Newtons)
A = area of contact = 4 [cm²]
But first we must convert from cm² to m²
A = 0.0004 [m²]
Also, the weight should be calculated as follows:
where:
m = mass = 60 [kg]
g = gravity acceleration = 9.81 [m/s²]
Now replacing:
And the pressure:
Because 1 [Pa] = 1 [N/m²]
Explanation:
It is given that,
= -40 mi/h, = -40 mi/h
The negative sign indicates that x and y are decreasing.
We have to find . Equation for the given variables according to the Pythagoras theorem is as follows.
Now, we will differentiate each side w.r.t 't' as follows.
or,
So, when x = 4 mi, and y = 3 mi then z = 5 mi.
As,
=
=
= 52
Thus, we can conclude that the cars are approaching at a rate of 52 mi/h.