1. A 40,000 kg plane is accelerating at a rate of 4m/s2. How much force does the engine put forth?

Alpha particles have positive charge, beta particles have negative charge, and answer 4 just doesn’t make sense. thus, you are left with only one possible answer.

Standing in the sunlight and feeling the heat on your face (uv radiation is entering the skin, converting to infrared radiation, and is absorbed by your tissues)orstanding near a fire and feeling the heat on your skin (infrared radiation transfer)

Not a  mixture of two common elements that can be separated by physical means.

Answerit is not a renewable energy source;