Question

Which graph correctly represents the variation of acceleration due to gravity (g) with depth (d) below Earth's surface?

Options

• An exponentially decreasing curve

• A straight line with a positive slope

• A straight line with a negative slope (linear decrease)

• A parabolic curve opening downward

Answer 1

A straight line with a negative slope (linear decrease)

Explanation:

Since g_d = g (1 - \[\frac {d}{R}\]), gravity decreases linearly as depth increases. On a graph of g_d vs d, this appears as a straight line sloping downward, starting at g (when d = 0) and reaching 0 (when d = R, i.e., at Earth's centre).