Answer:
B. QC > 0; QH < 0
Explanation:
Given that there are two reservoir of energy.
Sign convention for heat and work :
1.If the heat is adding to the system then it is taken as positive and if heat is going out from the system then it is taken as negative.
2. If the work is done on the system then it is taken as negative and if the work is done by the system then it is taken as positive.
From hot reservoir heat is going out that is why it is taken as negative

From cold reservoir heat is coming inside the reservoir that is why it is taken as positive

That is why the answer will be
,
It is A. a refrigerator cause a alternating current is current that doesn't stop and the refrigerator is plug into the wall.
False?
science can be a motivation out of curiosity AND societal needs.
For example:battery operated cars, are a curiosity and beneficial to the earths environment
Explanation:
a) How much work is done by gravity?
- w = f x d
- w = 950 x 10 x 5.5 = 52250j
b) How much work is done by tension?
- v²=u²+2as
- 0.75²=0.25²+2a x5.5
- 0.56=0.06+2a x5.5
- 2a x5.5 = 0.56 - 0.06
- 2a x 5.5 =0.5
- 11a=0.5
- a = 0.5/11 = 0.05m/s²
w = f x d
w = 950 x 0.05 x 5.5 = 261.25j
There are approximately two hundred and twenty-five point seven five calories from using 945 j of heat
A: 225.75