Select all the correct answers a strong magnetic field surrounds earth. how does earth’s magnetic field humans? a. it holds people’s belongings thigh to the earth’s surface. b. it’s responsible for cycling water through earth’s four spheres. c. it keeps the solar wind from reaching earth. d. it people navigate using a compass. e. it cool earths surface.

Visualize the problem and identify special cases first examine the problem by drawing a picture and visualizing the motion. apply newton's 2nd law, ∑f⃗ =ma⃗ , to each body in your mind. don't worry about which quantities are given. think about the forces on each body: how are these consistent with the direction of the acceleration for that body? can you think of any special cases that you can solve quickly now and use to test your understanding later? one special case in this problem is if m2=0, in which case block 1 would simply fall freely under the acceleration of gravity: a⃗ 1=−gj^.