A mountain bike is moving along a flat path at constant velocity. At some instant, the rider (weight = 670 N) applies pedal and hand forces, as shown in figure part a.

(a) Find reaction forces at the front and rear hubs. (Assume that the bike is pin supported at the rear hub and roller supported at the front hub.)

(b) Find internal stress resultants N, V, and M in the inclined seat post (see figure part b).

(c) If P₁ remains at 1700 lb and P₂ is set at 2260 lb, what new thickness of BC will result in the same compressive stress in both parts?

Transcribed Image Text:

241 mm Origin at B (0, 0, 0) HB 254 mm- 670 N 15.30 L 45 N at 30° to vertical on each grip 254 mm VB 1021 mm 90 Nat 5° 660 mm- 1130 mm VE F 752 mm X 200 N at 15° to vertical