Question

Question 1 10 pts A 70,0 Kg person on a parachute is descending with a terminal velocity of 8.00 m/s. The person tries to avoid leg injury after touch down by crouching down by 60.0 cm. Calculate the total stress on leg bones if the effective cross sectional area of bones is 6 cm? Assume the breaking stress of the bone is 1.00 x 10'dyn/cm2, and the Young's modulus is 14.0x1010 dyn/cm² Note that: 10^2 is same as 102 3.1 x 10^7 N/m^2 6.1 x 10^7 N/m^2 10^10 dyn/cm^2 0.60 x 10^10 dyn/cm^2 5.01 x 10^9 dyn/cm^2 7.12 x 10^7 dyn/cm^2 6.22 x 10^7 dyn/cm^2

Answer 1

given m= 70 kg I u= 8mls = initial speed "V =0 mls - final speed s = 6o.cm = Stopping s = 60 m=0.6m distance.

Retandation PAGE NO a=v?_u21 DATE zs a= (0,² (8) ² (22 (0.6) a= -53.3 m/s2 - Breaking Stress B = Fonce Area 6 cm² (70)(53.3) (6) (10 2,² = 6218333. N/m2 - 6. 28100 N/m2 = 6.20 100 x 105 dyne) Floormi? = 6.2x10" dyne dyne 6.2810 Lastoption is correct