If velocity is positive, which would most likely yield a negative acceleration?
a. a final velocity that is faster than an initial velocity.
b. a time that is less than a half hour.
c. an initial velocity that is faster than a final velocity.
d. a time that is greater than a half hour.

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.