Hi there!
We know that:
Force due to gravity = Mgsinθ
Force due to friction = μMgcosθ
Let the positive direction be directed in the direction of the block's acceleration, which is downward.
Thus:
ΣF = Mgsinθ - μMgcosθ
Solving for acceleration requires diving all terms by the mass, so:
a = gsinθ - μgcosθ
Substitute in given values. (g = 9.8 m/s²)
a = 9.8sin(30) - 0.3(9.8)cos(30) = 2.354 m/s²
(a) Zero
The maximum efficiency (Carnot efficiency) of a heat engine is given by

where
is the low-temperature reservoir
is the high-temperature reservoir
For the heat engine in the problem, we have:


Therefore, the maximum efficiency is

(b) Zero
The efficiency of a heat engine can also be rewritten as

where
W is the work performed by the engine
is the heat absorbed from the high-temperature reservoir
In this problem, we know

Therefore, since the term
cannot be equal to infinity, the numerator of the fraction must be zero as well, which means
W = 0
So the engine cannot perform any work.
I would say D) melting point.
Answer:
data storage, OLEDS, and wires
Explanation: