Fig 5.28 shows a non uniform rod abcd resting on a rough peg at c. r1 and r2 are the normal reactions on the rod by the peg and the wall respectively. f is the frictional force exerted by the peg on rhe rod . w is the weight of the rod .

explain why f has no turning effect on the rod .

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.