(a) What force should the woman in Figure 9.45 exert on the floor with each hand to do a push-up? Assume that she moves up at a constant speed. (b) The triceps muscle at the back of her upper arm has an effective lever arm of 1.75 cm, and she exerts force on the floor at a horizontal distance of 20.0 cm from the elbow joint. Calculate the magnitude of the force in each triceps muscle, and compare it to her weight. (c) How much work does she do if her center of mass rises 0.240 m? (d) What is her useful power output if she does 25 pushups in one minute?

Solution 37PE Step-by-step solution Step 1 of 5 (a) Consider the figure shown in 5.48, Draw the free body of diagram as given below, Step 2 of 5 Apply the second condition of equilibrium that is net applied torque around pivot point is zero, Here, is weight of women and is reaction force. Substitute 50.0 kg for , 0.90 m for and 1.50 m for solve for , Force is same on both hands so force on each hand is, Step 3 of 5 (b) Calculate the force in the triceps muscle by equating torque around pivot point, Ratio between forces in the triceps muscle to the weight,