Related questions
Consider a person serving a platter of hot food to their family who is gathered around a table. When holding theplatter, the person can choose how to hold the platter in front of them and would like compare the differences between position 1 and position 2 as shown below. In position 1, the shoulder is at 0 degrees while the elbow is at 90 degrees and in position 2, the arm is flexed as shown.
a.) Consider the elbow joint and draw free body diagrams for each of the positions shown, including gravitational forces (consider the weight of the combined forearm and hand), elbow flexor forces, and the joint contact force.
b.) Use the information provided below to solve for the magnitude of the elbow flexor force (in Newtons) for positions 1 and 2, the magnitude of the joint contact force (in Newtons), and the angle that the joint contact force makes with respect to the horizontal axis.
• The platter of food weighs 7 lbs; the person weighs 175 lbs, and the person is 5’8” tall.
• θ = 130 degrees and the insertion point of the elbow flexor is 3.5 cm away from the elbow joint.
• Based on anthropometric data, the combined weight of the forearm and hand make up 2.2% of the total body weight.
• Additional anthropometric data is provided in Figure 2 to help you determine the moment arms of the forearm + hand (consider them one segment) and the platter. Assume that the platter is held in the middle of the hand.
force analysis of elbow flexors. In anatomical mechanics, the forearm and elbow joint are often considered as a lever system whose fulcrum is located at the elbow joint. In contrast with mechanical leverage, the anatomical lever system usually has more than one unknown input force for the desired output performance. These forces are internal or muscle forces. There are three elbow flexors, involved in elbow flexion motion: (1) the brachioradialis, (2) the brachialis, and (3) the biceps. A number of elbow total replacements are available at present; however, the literature on biomechanical analysis of elbow motion, particularly the kinetic study, is scant.
Step by stepSolved in 3 steps with 1 images
- Next, imagine that a bullet impacts the block that you see and embeds itself. Let's say that you know the speed of the bullet just before it hits and also the mass of the bullet. Explain, with words and equations, how you would determine the angle theta. eed to know i L-h L Center of Pendulum catcharrow_forwardYou are on a pirate ship and being forced to walk the plank (Figure 1). You are standing at the point marked C. The plank is nailed onto the deck at point A, and rests on the support 0.75 m away from A. The center of mass of the uniform plank is located at point B. Your mass is 85 kg and the mass of the plank is 45 kg. Part A What is the minimum downward force the nails must exert on the plank to hold it in place? Express your answer to two significant figures and include the appropriate units. |Fnails|= for Part A for Part Vndo for Part redo for Part A ret for Part A keyboard shortcuts Value Unitsarrow_forwardI Review Constants Periodic Table (Figure 1) In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall.. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes well, the passengers will "stick" to the wall and not slide. Clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. Part A What is the minimum rotational frequency, in rpm, for which the ride is safe? Express your answer in revolutions per minute. Figure 1 of 1 • View Available Hint(s) f = rpm Submitarrow_forward
- Please provide the correct answerarrow_forwardA person pushes a box along the ground. The box has the force diagram shown below. Examine the force diagram to answer the following questions: a. Is the box in equilibrium? If so explain how you can tell. If not, explain why not. b. If the person wants the box to move at constant velocity, should they adjust their pushing on the block? If so, explain how they should change their push. If not, explain why they should change nothing about their pusharrow_forwardPlease solve this question with a free body diagram. Don't make any kind of mistakesarrow_forward
- Consider the system in the picture below: a cart of mass M with a static friction coefficient u is connected through a massless string to a hanging mass m. M is a capital letter, m is lower case. Write them as such, or vour equations will be confusing, M We want to find the maximum value of the hanging mass m such that the system is in equilibrium. 1. Free body diagram (FBD): Draw a FBD for each: the Cart and the hanging mass. Clearly show all the forces. 2. Clearly write the equilibrium equations for the cart in the horizontal and vertical direction. 3. Clearly write the equilibrium equation for the hanging mass. 4. Solve the system of the three equations above for the hanging mass m. Show your calculation to get credit. 5. What would happen if mass m exceeds this value? Explain.arrow_forwardPlease see the enclosed imagearrow_forwardA fisherman has a fish hooked on his line. At first, the pole is horizontal, as shown on the left. Later, the fisherman tilts his pole as shown on the right. 2 m- 2 m- 20° 20° 100 N 100 N Consider an axis of rotation that is perpendicular to the page and passes through the center of the fisherman's hand. In which figure is the torque exerted by the fish the largest? In the figure on the left. In the figure on the right. It is the same in both figures. It is impossible to tell from the information given.arrow_forward
- Please just show work C and Darrow_forwardIn the figure at the right is shown three graphs of the shapes of the same taut elastic string in three different circumstances, labeled A, B, and C. In some of the problems below, the string represents a guitar string, tied down at both ends, while in others, it is part of a very long telephone wire whose ends are not shown. Be careful to note which is which for each problem! The string is light enough that the effects of gravity can be ignored. In each case, the bit of string at the position x = 23 cm is painted blue. 4. Suppose that graph C represents part of a long wire, under tension, and is showing a left traveling wave at a particular instant. What can you say about the velocity of the blue bead in case C at the instant shown? a. It is upward. b. It is downward. c. It is 0. d. You cant say anything from the information given. 5. Suppose that graph C represents part of a long wire, under tension, and is showing a left traveling wave at a particular instant. What can you say…arrow_forward