Question

A gymnast weighing 750 N executes the iron cross. The ring exerts an upward force on...

A gymnast weighing 750 N executes the iron cross. The ring exerts an upward force on the arm of 375 N. The force exerted by the shoulder joint is R, while the muscles exert a total force of M on the arm. M acts at an angle of 45 degrees below the horizontal at a distance of 4 cm from the shoulder joint. The distance from the shoulder joint to ring is 70 cm. Ignore the weight of the arm. Note that one ring supports half the weight of the body.

a) calculate the magnitude of force M

b) calculate the magnitude and direction of the reaction force R

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Using the shoulder joint as the point of rotation. Then...
.
torque due to force from ring - torque due to Fm = 0
.
375 * 70 - Fm* 4 * sin45 = 0
.
Fm = 9279.4 Newtons
Fr cos(θ) = 9279.4*sin45 = 6562.5
Fr sin(θ) +375 = 9279.4*cos45 = 6562.5
Fr sin(θ) = 6187.5
θ = direction of R = 43.315 degrees

Fr = 9019.5 N

Add a comment
Know the answer?
Add Answer to:
A gymnast weighing 750 N executes the iron cross. The ring exerts an upward force on...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • Constants A 71.0 kg weight lifter is doing arm raises using a 7.50 kg weight in...

    Constants A 71.0 kg weight lifter is doing arm raises using a 7.50 kg weight in her hand. Her arm pivots around the elbow joint, starting 40.0 below the horizontal. (See the figure(Figure 1).) Biometric measurements have shown that both forearms and the hands together account for 6.40 % of a person's weight. Since the upper arm is held vertically, the biceps muscle always acts vertically and is attached to the bones of the forearm 5.50 cm from the elbow...

  • A 75.0 kg weight lifter is doing arm raises using a 7.50 kg weight in her...

    A 75.0 kg weight lifter is doing arm raises using a 7.50 kg weight in her hand. Her arm pivots around the elbow joint, starting 40.0 below the horizontal. (See the figure (Figure 1).) Biometric measurements have shown that both forearms and the hands together account for 5.75% of a person's weight. Since the upper arm is held vertically, the biceps muscle always acts vertically and is attached to the bones of the forearm 5.50 cm from the elbow Part...

  • A negative charge of -0.590 μC exerts an upward 0.900-N force

     A negative charge of -0.590 μC exerts an upward 0.900-N force on an unknown charge that is located 0.500 m directly below the first charge. Part A What is the value of the unknown charge (magnitude and sign)? Part B What is the magnitude of the force that the unknown charge exerts on the -0.590 μC charge?

  • A charge of -0.550 μC exerts an upward 0.180- N force on an unknown charge 0.320...

    A charge of -0.550 μC exerts an upward 0.180- N force on an unknown charge 0.320 m directly below it. 1)What is the unknown charge (magnitude and sign)? 2)What is the magnitude of the force that the unknown charge exerts on the charge of magnitude -0.550 μC ?

  • A charge of -0.540 μC exerts an upward 0.150-N force on an unknown charge 0.290 m...

    A charge of -0.540 μC exerts an upward 0.150-N force on an unknown charge 0.290 m directly below it. What is the unknown charge (magnitude and sign)? What is the magnitude of the force that the unknown charge exerts on the charge of magnitude -0.540 μC ? What is the direction of the force that the unknown charge exerts on the charge of magnitude -0.540 μC ?

  • Exercise 21.14 Constants Part A A charge of-0.500 μC exerts an upward 0.180-N force on an...

    Exercise 21.14 Constants Part A A charge of-0.500 μC exerts an upward 0.180-N force on an unknown charge 0.340 m directly below it. What is the unknown charge (magnitude and sign)? Q- Submit est Answer Part B What is the magnitude of the force that the unknown charge exerts on the charge of magnitude-0.500 μC ? Submit Part C What is the direction of the force that the unknown charge exerts on the charge of magnitude-0.500 μC ? upward downward...

  • 2, A positive charge of +0.35 «C exerts an upward 0.600 N force on an unknown...

    2, A positive charge of +0.35 «C exerts an upward 0.600 N force on an unknown charge that is located 0.500 m directly below the first charge. What are (a) the value of the unknown charge (magnitude and sign); (b) the magnitude and direction of the force that the unknown charge exerts on the +0.350uC charge?

  • The figure below shows a human arm that weighs 39.3 N. The arm is extended outward...

    The figure below shows a human arm that weighs 39.3 N. The arm is extended outward and is motionless. The gravitational force Fg on the arm acts at point A, a distance of 0.290 m from the shoulder joint, which is represented by point O. The shoulder pushes down and to the right on the humerus bone of the arm with a force Fs at point O, at an angle θ as shown. The deltoid muscle pulls back on the...

  • A negative charge of -0.565 μC exerts an upward 0.180 N force on an unknown charge...

    A negative charge of -0.565 μC exerts an upward 0.180 N force on an unknown charge 0.280 m directly below it. Part A What is the unknown charge? PART B: What is the magnitude of the force that the unknown charge exerts on the -0.565 μC charge? PART C: What is the direction of the force that the unknown charge exerts on the -0.565 μC charge?

  • Exercise 21.14 Constants Part A A charge of -0.500 C exerts an upward 0.220-N force on...

    Exercise 21.14 Constants Part A A charge of -0.500 C exerts an upward 0.220-N force on an unknown charge 0.320 m directly below it. What is the unknown charge (magnitude and sign)? e- Submit Request Answer Part B What is the magnitude of the force that the unknown charge exerts on the charge of magnitude-0.500 μ C ? Submit Request Answer

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT