An astronaut is floating in outer space. She needs to find her air tanks or she will be doomed. She only has time to unlock one of the three cases. She knows that the air tanks are in the most massive tank. How can she find out which case is the most massive? Weigh all of the cases using a scale.

Determine which case has the greatest volume by multiplying height x width x length.

Apply an equal amount of force to all three cases and see which has less acceleration.

It is impossible to tell which is which.

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^.