The second one, air is a poor conductor. If it weren't it wouldn't be used as such in construction. It's not the best insulator, but is quite efficient, and much cheaper to include a layer of air inside a wall than to add additional layers of asbestos :)
Answer: Always accelerates in a downward direction
Explanation: Gravity is pulling the ball downward
Solution
x(t) = 8 cos t, x(5π/6)= 8 cos(<span>5π/6)
</span>cos(5π/6)=cos(3π/6 + 2π/6 )=cos(π/3 +π/2)= - sin π/3 (cos (x+<span>π/2)= -sinx)
</span>x(t) = -8sin <span>π/3 = - 4 .sqrt3
</span>v(t) = -8sint = -8sin (π/3 +<span>π/2)= -8 cosπ/3 </span>(sin (x+π/2)= cosx)
v(t) =<span> -8 cosπ/3 = -8/2= - 4
</span>a(5π/6) = - 8cost = -(- sin π/3)= 4 .<span>sqrt3
</span>a(5π/6) = 4 .<span>sqrt3</span>
Answer:
Aluminium, Nickel, Cobalt and Iron plus varying levels of Copper, Titanium and Niobium.
MAGNETIC: Alni, Alcomax, Hycomax, Columax, and Ticonal.