Ummm because it need space to move around and function
<span>To get that, find the time when slope equals to 0, use the derivate theory from calculus.
s = 8 cos t + 9 sin t, t ≥ 0
s' = -8 sin t + 9 cos t (this is slope)
0 = -8 sin t + 9 cos t
8 sin t = 9 cos t
tan t = 9/8
t = 48.37 seconds</span>
Answer:
a) The maximum contact pressure is 274.58 MPa and the width of contact is 0.058 mm
b) The maximum shear stress is 82.37 MPa at a distance of 0.023 mm
Explanation:
Given data:
L = 20 mm
F = 250 N
r₁ = 10 mm
r₂ = 15 mm
v = 0.3
E = 2.07x10⁵ MPa

a) The maximum contact pressure is:

The width of contact is:

b) According the graph elastic stresses below the surface, for v = 0.3, the maximum shear stress is
T = 0.3*P = 0.3 * 274.58 = 82.37 MPa
At a distance of
0.8*b = 0.8*0.029 = 0.023 mm
Since he wonders, then according to the formal, methodical procedures of scientific inquiry, he should not go running off and trying stuff before he <em>forms a hypothesis that can be tested.</em>
In his mind, at some point, he should say to himself <em>"Self ! It seems to me that if salt is added to water, it makes the water boil at a higher temperature than pure water does."</em>
And only THEN, with this statement in mind, he's ready to design an experiment to test it.