Question

MAE 211: Engineering Mechanics 1. A 350-N force acts on a brake pedal, as shown in (a) If the pedal is in equilibrium in the position shown, what is the tension in the spring? (b) If the total de to 5 mm when the 350-N pedal force is at A is to be limited applied, what is the minimum required spring stiffness k? c) What are the pin reactions at D? First, draw the FBDI! 100 mm 50 mm 40 mm 350 N 30 mm 20° 20 mm

Answer 1

(a)Tailing moment with respect to D Rightarrow 350 cos @D times 70 + 350 sin 2D times (20) = F_s times 50 rightarrow (1) F_s = Tension in the spring = T_AB Rightarrow T_AB = 7 cos 20 times 70 + 7 sin 20 times (20) = 460.449 + 47.88 T_AB = 508.33N (b)If the total deflection at A is to be limited to be 5mm Rightarrow 5 Tension in the spring T_AB = kx = k times 5 substitute this in(1) Rightarrow 5k times 50 = 350 cos 2D times (70) + 350 sin 2D times (2D) Rightarrow 5k = 508.33 Rightarrow k = 101.66 N/mm