During a car crash, the forearms of a passenger are slammed against the dashboard.
Each arm comes to rest from an initial speed of 80 km/h in 5 ms. If the arm has an effective
mass of 3 kg and bone material can withstand a maximum compression stress of 16 x 107
Pa,
will the arms withstand the crash? (cross-section of calcified area of the two forearm bones,
ulna and radius, is approximately 2.4 cm2
)
F = m (deltav/ deltat)
Deltav = 80 km/h × [1000 (m/km) / 3,600 (s/hr)] = 22.2 m/s
Delta t = 5 ms = 5 × 10-3
s
Delta F = 3 kg × [22.2 (m/s) / 5 × 10^-3
s] = 1.33 × 10^4
N
Bone has a Young's modulus of about 18 x 109 Pa. Under compression, it can withstand a stress of about 160 x 106 Pa before breaking. Assume that the femur is 0.5 m long and calculate the amount of compression this bone can withstand without breaking. aB = Y EB = Y (deltaL / Lo) deltaL = (aB / Y) Lo here aB = 160 × 106 Pa; Y = 18 × 109 Pa deltaL = (160 × 106 Pa / 18 × 109 Pa) 0.5 m = 4.3 × 10-3 m = 4.3 mm
Bones can withstand a considerable amount of pressure. On average, bones can withstand compressive forces of around 180 Mpa (megapascals) to 230 Mpa. However, this can vary depending on the type of bone and the direction of the force applied.
Bone is typically weaker under tension forces compared to compression forces. This means that bone is more likely to break or fracture when subjected to stretching or pulling forces rather than pushing or compressive forces.
it means if the mineral is fragile or not, and this all depends on the Mohs hardness scale
Bone is strong under tension due to its composition of collagen fibers, which provide flexibility and resistance to stretching, and mineralized bone matrix, mainly made of calcium and phosphorus, which give it hardness and strength. This combination allows bone to withstand tension without breaking easily.
A femur bone can withstand roughly 4000 N of force.
Compact Bone
Bone has a Young's modulus of about 18 x 109 Pa. Under compression, it can withstand a stress of about 160 x 106 Pa before breaking. Assume that the femur is 0.5 m long and calculate the amount of compression this bone can withstand without breaking. aB = Y EB = Y (deltaL / Lo) deltaL = (aB / Y) Lo here aB = 160 × 106 Pa; Y = 18 × 109 Pa deltaL = (160 × 106 Pa / 18 × 109 Pa) 0.5 m = 4.3 × 10-3 m = 4.3 mm
Spongy bone
Cortical bone, also known as compact bone, is the type of bone adapted to withstand stresses that arrive from a limited range of directions. It is dense and forms the outer shell of most bones in the body, providing strength and protection.
It depends on the bone. The femur (thigh bone) is much stringer than other bones.
Yes. Collagen is a mineral in your bone and marrow that makes your bones flexible yet strong enough to withstand a blow. :)The organic material in bone is collagen. This is a protein which forms long, flexible fibres in the matrix surrounding the bone cells. It is estimated that collagen makes up 25% of the total protein in the body.
A compression fracture occurs when the bone is crushed or pressed together, often resulting in loss of height in the bone. This type of fracture is commonly seen in osteoporotic bones. Treatment involves stabilizing the bone and managing pain.
Bones can withstand a considerable amount of pressure. On average, bones can withstand compressive forces of around 180 Mpa (megapascals) to 230 Mpa. However, this can vary depending on the type of bone and the direction of the force applied.
bone
Bones are made up of a matrix of collagen fibers and calcium crystals, which provide both flexibility and strength. The hollow structure of bones, filled with marrow, also contributes to their lightweight nature. Additionally, the arrangement of compact and spongy bone tissues distributes forces and enhances the bone's ability to withstand compression and tension.
Compression fractures can be caused by osteoporosis, trauma inflicted on the back, and tumors that have started in the bone. Tumors that occur in the spine also cause compression fractures.