Question

To practice Problem-Solving Strategy 8.1 Static equilibrium problems. and Felbow. Part 1 When you lift an object by moving only your forearm, the main lifting muscle in your arm is the biceps. Suppose the mass of a forearm is 1.20 kg. If the biceps is connected to the forearm a distance dbiceps = 2.50 cm from the elbow, how much force Fbiceps must the biceps exert to hold a 500 g ball at the end of the forearm at distance dball = 32.0 cm from the elbow, with the forearm parallel to the floor? How much force Felbow must the elbow exert? (Figure 1) What is the magnitude of the force exerted by the biceps Fbiceps ? What is the magnitude of the force exerted by the elbow Felbow? Express your answers in newtons separated by a comma. VO ADA O ? igure < 1 of 1 > Fbiceps , Felbow = N, N Submit Request Answer

Answer 1

Pa :-) som - fbiceps dbiceps Felbow Wrarearm Wball. k dball torque = force x perpendicular distance. take moment about the elbow and equate the moment. _ As So, wball & abals & Wrerears & (dalt). - & biceps x d biceps mball xgx d ball & Forearm gxdball - Friceps x 2.50 x 10² m (sooz ming x 9.3 m/+* 31.0x10"m) +(1.2069*9.8m/*** 320x106) 10003 - thiceps x 2.50x102 m = 1.568 Nim + 1.8816 N.m - Ebiceps x 2.80 x 10 m. bicets = 137.984 N Equate the vertical forces: - Friceps - Felbow - W forearm - Wball o - 137.984N - Felbow - forearm & g-mball & g = 0 - Felbow = 137.984 (1.20kg x 9.8m/52)-(soog x1 kg x 9.8 m/5²) Felbow = 121.324 N ovog