Which factor does not affect the strength of an electromagnet

In which of the following cases is work being done on an object? question 2 options: pulling a trailer up a hill carrying a box down a corridor suspending a heavy weight with a strong chain pushing against a locked door

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Need asap ‼️ 20 pts which gravitational force field diagram is drawn correctly? (answers in pictures below)