A woman lifts a 7.2-kg barbell in each hand with her arm in a horizontal position...

A woman lifts a 7.2-kg barbell in each hand with her arm in a horizontal position at the side of her body and holds it there for 3 s. The deltoid attaches 13 cm from the shoulder joint and makes a 13∘ angle with the humerus. The barbell in her hand is 0.55 m from the shoulder joint, and the center of mass of her 4.0-kg arm is 0.24 m from the joint.

1. Determine the magnitude of the force that the lifter's shoulder joint exerts on her humerus. Express your answer with the appropriate units.

2. Determine the direction of the force (measured clockwise from the positive x-axis) that the lifter's shoulder joint exerts on her humerus. Express your answer with the appropriate units.

I already found the force the deltoid exerts on the humerus (with help) but I am not sure how to even set up these problems. Any help is great, thank you!

Expert Solution

b) Angle is,

= Tan^-1[-261/1607]

= -9.225^o with +x axis,

9.225^o Clockwise from +x axis .

I hope you understood the problem and got your answers, If yes rate me!! or else comment for a better solutions.

genius_generous answered 8 months ago

To develop muscle tone, a woman lifts a 3.30 kg mass held in her hand. She...

To develop muscle tone, a woman lifts a 3.30 kg mass held in her hand. She uses her biceps muscle to flex the lower arm through an angle of 60.0°. Ignore gravity. (a) What is the angular acceleration, in rad/s2, if the mass is 24.0 cm from the elbow joint, her forearm having a moment of inertia of 0.250 kg · m2, and the muscle force being 830 N at an effective perpendicular lever arm of 2.90 cm? (b) How...

An athlete at the gym holds a 2.0 kg steel ball in his hand. His arm...

An athlete at the gym holds a 2.0 kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg . What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? What is the magnitude of the torque about his shoulder if he holds his arm straight, but 35 degrees below horizontal?

A 65 kg woman stands at the rim of a horizontal turntable having a moment of...

A 65 kg woman stands at the rim of a horizontal turntable having a moment of inertia of 520 kg·m2 and a radius of 2.0 m. The turntable is initially at rest and is free to rotate about a frictionless vertical axle through its center. The woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of 1.5 m/s relative to the Earth. (a) In what direction and with what angular speed...

A 60.0-kg woman stands at the western rim of a horizontal turntable having a moment of inertia of 500 kg ?

A 60.0-kg woman stands at the western rim of a horizontal turntable having a moment of inertia of 500 kg ? m2 and a radius of 2.00 m. The turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center. The woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of 1.50 m/s relative to the Earth. Consider the woman–turntable system as motion begins....

A 54.0-kg woman stands at the western rim of a horizontal turntable having a moment of...

A 54.0-kg woman stands at the western rim of a horizontal turntable having a moment of inertia of 490 kg · m2 and a radius of 2.00 m. The turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center. The woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of 1.50 m/s relative to the Earth. Consider the woman–turntable system as motion begins....

A 50.0-kg woman stands at the rim of a horizontal turntable having a moment of inertia...

A 50.0-kg woman stands at the rim of a horizontal turntable having a moment of inertia of 420 kg · m2 and a radius of 2.00 m. The turntable is initially at rest and is free to rotate about a frictionless vertical axle through its center. The woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of 1.50 m/s relative to the Earth. (a) In what direction does the turntable rotate?...

In a horizontal spring-mass configuration, the position of the 0.44 kg mass is described by [x...

In a horizontal spring-mass configuration, the position of the 0.44 kg mass is described by [x = (0.49 m) sin(2.39t)] a) What is in meters the amplitude of these oscillations? b) What is in m/s the maximum speed of the mass under these conditions? c) What is in Joules the spring potential energy stored in this system when the spring is stretched at a maximum? d) What is in Joules the kinetic energy of the mass when the spring is...

In each hand you hold a 0.17-kg apple. What is the gravitational force exerted by each...

In each hand you hold a 0.17-kg apple. What is the gravitational force exerted by each apple on the other when their separation is each of the following? (a) 0.40 m _______ N (b) 0.80 m _______ N A communications satellite with a mass of 500 kg is in a circular orbit about the Earth. The radius of the orbit is 46,000 km as measured from the center of the Earth. (a) Calculate the weight of the satellite on the...

M.D. is a 50-year-old woman whose routine mammogram showed a 2.3- × 4.5-cm lobulated mass at the 3 o’clock position in her left breast.

ScenarioM.D. is a 50-year-old woman whose routine mammogram showed a 2.3- × 4.5-cm lobulated mass at the 3 o’clock position in her left breast. M.D. underwent a stereotactic needle biopsy and was diagnosed with invasive ductal carcinoma, estrogen and progesterone receptor positive, HER-2 negative. The staging workup was negative for distant metastasis. Her final staging was stage IIB. She had a modified radical mastectomy with axillary lymph node dissection. The sentinel lymph node and 4 of 16 lymph nodes were...

A slab of ice floats on a freshwater lake. What minimum volume must the slab have for a 45.0 kg woman to be able to stand on it without getting her feet wet?

Question