It takes 56.5 kilojoules of energy to raise the temperature of 150 milliliters of water from 5 °c to 95 °c. if you use an electric water heater that is 60% efficient, how many kilojoules of electrical energy will the heater actually use by the time the water reaches its final temperature?

If 56.5kJ are needed to raise the temp by 90°C and if the heater is 60% efficient that means that:

60% X y = 56.5kJ

where y is the electrical energy in kJ that the heater will use.

y = 94.2kJ  

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.