A. because everything is balanced.
Answer:
C. The block and the sphere would have the same weight.
Explanation:
If both the block and the sphere weigh 7 kilograms then they have the same weight. They may look different, but they both weigh 7 kilograms.
Answer:

Explanation:
Position of charge 3q is x = 0
position of charge -2q is x = a
so here we know that
when two charges are of opposite nature then the electric field will be zero on the line joining the two charges at the position near to smaller magnitude charge
So here the electric field will be zero if the field due to 3q is counterbalanced by field due to -2q
so here we can say





so we will have

so the x coordinate of this position is given as

(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.
Do 25-14 and you will get your answer