A heat engine is supplied with 386.0 cal and rejects 235.0 cal in the exhaust. How many joules of mechanical work was done?

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.