You response is within 10% of the correct value. This may be due to roundofr err

Question

You response is within 10% of the correct value. This may be due to roundofr error, or you could have a mistake your caloulation. Carry out all intermediate results to at least four-digit accuracy to minimize roundoff error, m Show My Work (Optional) Traumatic brain injury such as concussion results whem the head undergoes a very large acceleration. Generally, an acceleration less than 900 m/s2 lasting for any length of time will not cause injury, whereas an acceleration greater than 1000 m/s2 lasting for at least 1 ms will cause injury. Suppose a small child rolls off a bed that is 0.38 m abave the floor, If the floor is hardwood, the child's head is brought to rest in approximately 1.8 mm. If the Hoor carpeted, this stoppling distance is increased to about 1.1 cm. Calculate the magnitude and duration of the deceleration in both cases, to determine the risk of injury. Assume that the child remains horizontal during the fall to the foor. Note that a more complicated fall could resuit in a head velocity greater or less than the speed you Hardwood foor magnitude /s duration yo r-response differs from the correct answer by more than 100% ma You Carpeted floor duration EN ONmMaers Trom the correct answer by more than 10%. Double chieck your calculations. ms Show My Work (Optional) g Submit Answer Seve Progress Pracbce Anoiher Version My Notes Ask Your Teac 13. 1/1 points 1 Previous Answers SercCP11 2 XP006 An arrow is shot straight up in the air at downward at a speed of 3.00 m/s? 4.18 downwerd st a epeed of 3.0a m/e,air ot an nitisal speed of 38. mVs. er how much time is the arrow heading Show My Work Optional)

Explanation / Answer

Using 3rd equation of motion

V^2= 2* gh

V^2= 2*9.8*0.38

V= 2.73 m/s

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Forc hardwood

0= V^2- 2* a* d

a= 2.73^2/(2*1.8*10^-3)

a= - 2070.25 m/s^2

Duration

t= v/a= 2.73/2070.25= 1.318 ms

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For carpet

a= -2.73^2/(2*0.011)

a= - 338.77 m/s^2

Duration

t= 2.73/338.77= 8.06 ms

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Goodluck

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