(a) A 57-kg man steps out a window and falls (from rest) 1.1 m to a sidewalk. Wh

Question

(a) A 57-kg man steps out a window and falls (from rest) 1.1 m to a sidewalk. What is his speed just before his feet strike the pavement? m/s (b) If the man falls with his knees and ankles locked, the only cushion for his fall is an approximately 0 48-cm give in the pads of his feet. Calculate the average force exerted on him by the ground during this 0.48 cm of travel. This average force is sufficient to cause damage to cartilage in the Joints or to break bones. N What steps or reasoning did you use? Your work counts towards your score. You can submit show my work an unlimited number of times. Show My Work has not been graded yet.

Explanation / Answer

Given that

mass m=67 kg

distance x=1.1 m

height h=0.48 cm

basing on the concept of the laws of motion

now we find the speed just before strike

the speed v=[2gx]^1/2=[2*9.8*1.1]^1/2=4.6 m/s

now we find the average force execrted by him

the avergae force F=mv^2/2*h=67*4.6^2/2*0.0048

=147679.2 N

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.