A waiter holds two plates of food in one hand. His forearm has a mass of 2.8kg and the centre of mass of his forearm is located 11cm from his elbow joint. The centre of mass of the two plates is located 32cm from his elbow joint and the total mass of the two plates is 1.75kg. His bicep is attached to the bones of his forearm is 3.6cm from his elbow joint. Assume his forearm is held completely horizontal. a. What is the torque produced by the mass of the two plates? Torque = Nm b. What is the torque produced by the mass of the waiter's forearm? Torque = 0 c. What force must be exerted by the waiter's biceps muscle to ensure that the plates and forearm are motionless? Ny Force = Nm

A waiter holds two plates of food in one hand. His forearm has a mass of 2.8kg and the centre of mass of his forearm is located 11cm from his elbow joint. The centre of mass of the two plates is located 32cm from his elbow joint and the total mass of the two plates is 1.75kg. His bicep is attached to the bones of his forearm is 3.6cm from his elbow joint. Assume his forearm is held completely horizontal. a. What is the torque produced by the mass of the two plates? Torque = Nm b. What is the torque produced by the mass of the waiter's forearm? Torque = 0 c. What force must be exerted by the waiter's biceps muscle to ensure that the plates and forearm are motionless? Ny Force = Nm

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

Luc, who is 1.80 mm tall and weighs 950 NN, is standing at the center of a playground merry-go-round with his arms extended, holding a 4.0 kgkg dumbbell in each hand. The merry-go-round can be modeled as a 4.0-mm-diameter disk with a weight of 1500 NN. Luc's body can be modeled as a uniform 40-cmcm-diameter cylinder with massless arms extending to hands that are 85 cmcm from his center. The merry-go-round is coasting at a steady 35 rpmrpm when Luc brings his hands in to his chest. Afterward, what is the angular velocity, in rpmrpm, of the merry-go-round? The answer is not 31.6 rpm.
Luc, who is 1.80 mm tall and weighs 950 NN, is standing at the center of a playground merry-go-round with his arms extended, holding a 4.0 kgkg dumbbell in each hand. The merry-go-round can be modeled as a 4.0-mm-diameter disk with a weight of 1500 NN. Luc's body can be modeled as a uniform 40-cmcm-diameter cylinder with massless arms extending to hands that are 85 cmcm from his center. The merry-go-round is coasting at a steady 35 rpmrpm when Luc brings his hands in to his chest.
A 68 kg man is in the prone position while during pushups. His feet and hands are 95 cm and 42 cm away respectively from his center of mass. What is the normal force exerted by on each (a) hand and (b) foot?
Many years ago, automobiles were manufactured to be as rigid as possible, whereas today’s autos are designed to crumple upon impact. Why?
Treat the upper limb as one segment with a centre of mass 35.6 cm from the shoulder joint. The upper limb has a mass of 4.5 kg. Calculate the moment of force created by the upper limb
A girl and a boy stand at opposite ends of a 5 m long uniform board with mass 50 kg. The girl’s mass is 30 kg and the boy’s mass is 40 kg. Where is the center of mass of the girl/board/boy system measured relative to the girl?
ABCD is rectangle, in which AB = CD = 100 mm and BC = DA = 80 mm. Forces of 100 N each act along AB and CD and forces of 50 N each at along BC and DA. What is the resultant moment of the two couples?
Two balls are connected by a 150-cmcm-long massless rod. The center of mass is 35 cmcm from a 85 gg ball on one end. What is the mass attached to the other end?
An athlete holds a 7.5-kg shot put in his hand with his lower arm horizontal, as shown in thefigure. His lower arm has a mass of 2.8 kg and its center of gravity (or center of mass) is 12 cmfrom the elbow-joint pivot. How much force must the extensor muscle (which is FM in thefigure) in the upper arm exert on the lower arm? Choices: 500 N 2000 N 1500 N 2500 N 1000 N Show complete solution and free body diagram
A stick is resting on a concrete step with 1/3 of its total length ? hanging over the edge. A single ladybug lands on the end of the stick hanging over the edge, and the stick begins to tip. A moment later, a second, identical ladybug lands on the other end of the stick, which results in the stick coming momentarily to rest at ?=56.9∘ with respect to the horizontal, as shown in the figure. If the mass of each bug is 3.26 times the mass of the stick and the stick is 18.7 cm long, what is the magnitude ? of the angular acceleration of the stick at the instant shown? Use ?=9.81 m/s^2. ?=__________ rad/s^2
The forearm-hand complex weights 51N, and the center of mass is 0.17 m from the elbow joint. The person is holding a large wheel of cheese that weighs 98N. The center of mass of the cheese is 0.34 m from the elbow joint. The moment arm of the elbow flexors is estimated to be 0.03m from the elbow. The relative elbow angle is (angle between the humerus and the forearm) is 60°. What force must be exerted by the elbow flexors to keep the forearm in this static position (in N)?
Luc, who is 1.80 m tall and weighs 950 N, is standing at the center of a playground merry-go-round with his arms extended, holding a 4.0 kg dumbbell in each hand. The merry-go-round can be modeled as a 4.0-m-diameter disk with a weight of 1500 N. Luc's body can be modeled as a uniform 40-cm-diameter cylinder with massless arms extending to hands that are 85 cm from his center. The merry-go-round is coasting at a steady 35 rpm when Luc brings his hands in to his chest. Afterward, what is the angular velocity, in rpm, of the merry-go-round?