UK GCSE level age ~14-16, ~US grades 9-10 Biology revision notes re-edit 23/05/2023 [SEARCH]

Skeleton and muscles: 3. Weight lifted and force needed calculations based on the action of muscles e.g. antagonistic muscles of elbow joint

Doc Brown's Biology exam study revision notes

*

There are various sections to work through, after 1 they can be read and studied in any order.

INDEX of biology notes on the skeleton and muscles

*


(3) Weight lifted and force calculations based on the action of muscles

force and moment calculations of arm elbow joint force generated by biceps and triceps calculating force needed to lift raise a weight

Some example questions (answers)

ALL based on the diagram above for the antagonistic biceps and triceps muscles of the elbow joint

Assume the gravitational field constant is 10 N/kg

Question 1

 If d1 = 0.40 m, d2 = 5 cm, using the above diagram for help, and applying the principle of moments, calculate the minimum force needed by the biceps contraction to lift a weight of 20 N.

Question 2

 If d1 = 0.36 m, d2 = 0.06 m, using the above diagram for help, and applying the principle of moments, calculate the minimum force needed by the biceps contraction to lift a mass of 3 kg.

Question 3

 If d1 = 45 cm, d2 = 5 cm, using the above diagram for help, and applying the principle of moments, calculate the minimum force needed by the biceps contraction to lift a weight of 15 N.

Question 4

 If d1 = 48 cm, d2 = 6 cm, using the above diagram for help, and applying the principle of moments, calculate the minimum force needed by the biceps contraction to lift a weight of 2 kg.

Question 5

 If d1 = 0.50 m, d2 = 0.05 m, using the above diagram for help, and applying the principle of moments, if the maximum strength of a person's biceps muscle contraction creates a force of 150 N, calculate the maximum weight the person's arm can raise and hold.

Question 6

 If d1 = 0.60 m, d2 = 0.06 m, using the above diagram for help, and applying the principle of moments, if the maximum strength of a person's biceps muscle contraction creates a force of 180 N, calculate the maximum mass the person's arm can raise and hold.

Question 7

 If d1 = 0.50 m, d2 = 0.05 m, using the above diagram for help, and applying the principle of moments, if the maximum strength of a person's biceps muscle contraction creates a force of 200 N, calculate the maximum weight the person's arm can raise and hold.

Question 8

 If d1 = 0.40 m, d2 = 0.06 m, using the above diagram for help, and applying the principle of moments, if the maximum strength of a person's biceps muscle contraction creates a force of 240 N, calculate the maximum mass the person's arm can raise and hold.

(Answers)


WHAT NEXT?

TOP OF PAGE

INDEX of biology notes on the skeleton and muscles

INDEX of all my BIOLOGY NOTES

This is a BIG website, so try using the [SEARCH BOX], it maybe quicker than the many indexes!

email doc brown - comments - query?


UK KS3 Science Quizzes for KS3 science students aged ~11-14, ~US grades 6, 7 and 8

BiologyChemistryPhysics UK GCSE/IGCSE students age ~14-16, ~US grades 9-10

Advanced Level Chemistry for pre-university ~16-18 ~US grades 11-12, K12 Honors

Find your GCSE/IGCSE science course for more help links to all science revision notes

Use your mobile phone or ipad etc. in 'landscape' mode?

Website content Dr Phil Brown 2000+. All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. Exam revision summaries & references to science course specifications are unofficial.

Answers to the muscle force questions using the principle of moments

Remember 1 kg mass is equivalent to 10 N on the Earth's surface.

Q1 F1 x d1 = F2 x d2, convert cm to m, 20 x 0.40 = F2 x 0.05, F2 = 20 x 0.40 / 0.05 = 160 N

Q2 3 kg = 3 x 10 = 30 N, F1 x d1 = F2 x d2, convert cm to m, 30 x 0.36 = F2 x 0.06 x F2, F2 = 30 x 0.36 / 0.06 = 180 N

Q3 F1 x d1 = F2 x d2, convert cm to m, 15 x 0.45 = F2 x 0.05, F2 = 15 x 0.45 / 0.05 = 135 N

Q4 2 kg = 2 x 10 = 20 N, F1 x d1 = F2 x d2, convert cm to m, 20 x 0.48 = F2 x 0.06, F2 = 20 x 0.48 / 0.06 = 160 N

Q5 F1 x d1 = F2 x d2, F1 x 0.50 = 150 x 0.05, F1 = 150 x 0.05 / 0.50 = 15 N

Q6 F1 x d1 = F2 x d2, F1 x 0.60 = 180 x 0.06, F1 = 180 x 0.06 / 0.60 = 18 N, mass = 18 / 10 = 1.8 kg

Q7 F1 x d1 = F2 x d2, F1 x 0.50 = 200 x 0.05, F1 = 200 x 0.05 / 0.50 = 20 N

Q8 F1 x d1 = F2 x d2, F1 x 0.40 = 240 x 0.06, F1 = 240 x 0.06 / 0.40 = 36 N, mass = 36 /10 = 3.6 kg

TOP OF PAGE