Traumatic brain injury such as concussion results when the head undergoes a very large acceleration. Generally, an acceleration less than 800 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 above the floor. If the floor is hardwood, the child's head is brought to rest in approximately 2.1 mm. If the floor is carpeted, this stopping distance is increased to about 1.0 cm. Calculate the magnitude and duration of the deceleration in both cases, to determine the risk of injury. Assume the child remains horizontal during the fall to the floor. Note that a more complicated fall could result in a head velocity greater or less than the speed you calculate.

Hardfloor Mag:

Hardfloor Duration:

Carpet Floor Mag:

Carpetfloor Duration:

2 answers

find velocity when hitting the floor.
v^2=g*1m v= sqrt(9.8) m/s

Now, find the momentum change

find the acceleration
vf^2=vi^2+2ad
d= distance for each stop.
vi=sqrt(9.8) m/s
vf=0

a= 1/2 (9.8)distance= 4.9 m/s^2/distance
U didn’t even answer the question