Can someone please answer this question in simple terms and not over complicated. i know nothing about the subject. If you want to make a strong battery, should you pair two metals with high electron affinities, low electron affinities, or a mix? Explain your answer. (4 points)

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?