A solid steel ball of diameter 4 cm rolls off the edge of a lab table that is 1.20 m above the floor. A student models the ball as a point mass located at its center when calculating the time it takes to reach the floor. Taking g=9.8m⋅s−2, by approximately how much does the calculated fall time differ from the actual time required for the lowest point on the ball to touch the floor?
(a) About 0.004 s shorter than the actual time
(b) About 0.004 s longer than the actual time
(c) There is essentially no difference; the error is 0 s
(d) About 0.008 s shorter than the actual time