Question

Suppose the earth is a perfect sphere, spinning with its usual angular velocity, Ω. You are ~ standing on the surface of the earth, at 40 degrees N latitude, and you drop a rock. If you draw a line from the rock to the center of the earth, it would intersect the ground at a point X.

(a) Write down the forces on the rock, in your rotating reference frame, at the instant you let go of the rock, but before it starts moving.

(b) Using the forces you found in part 3(a), does the net force point exactly toward the X (i.e., exactly toward the center of the earth?) YES or NO (Circle one) If not, where does it point relative to the X (explain your answer qualitatively, in terms of north, south, east, and west of the X)?

(c) Write down any additional forces on the rock a short time after you drop it, when it is falling with finite velocity, but before it hits the ground. Will the rock land on the X? If not, where relative to the X will it land? (In both cases, explain your answer qualitatively, in terms of north, south, east, and west of the X. You do not have to calculate where the rock lands.)

Answer 1