physics please help me
posted by dan
The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop.
(a) What is the time interval during which a vaulter who has just cleared a height of 6.9 m slows to a stop?
(b) What is the time interval if instead the vaulter is brought to rest by a 19.2cm layer of sawdust that compresses to 4.6 cm when he lands?
(c) Qualitatively discuss the difference in average force the vaulter experiences from the two different landing pads. That is, which landing pad would exert the least force on the vaulter and why?

bobpursley
force*distance=1/2 mv^2=mgh
Olympics competition? Assume the vault was at 17 feet, or 5.2meters.
Energy to final stop: h=5.2m.1m=5.1m
or GPE lost= mass*g*5.1m
Work done on the bag=GPE lost
Force*distance=mass*g*5.1
forceaverage= mass*g*5.1/1
now, consider momentum:
forceaverate*time= change in momentum
time= mass*vi/mass*g*5.1
= sqrt(2g*5.1)/g*5.1=sqrt (2/(g*5.1))
= .2seconds
Respond to this Question
Similar Questions

Physical science
A 50 kg pole vaulter falls from rest from a height of 5 meters onto a foam rubber pad. The pole vaulter comes to rest 0.22 seconds after landing on the pad. Calculate the athlete's velocity just before reaching the pad. Answer in m/s. … 
physics help
The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop. (a) What is the time interval during … 
please help dont know how to solve
The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop. (a) What is the time interval during … 
physics
The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop. (a) What is the time interval during … 
physics
The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop. (a) What is the time interval during … 
physics
please help i cannot figure this out A 0.27 kg ball of dough is thrown straight up into the air with an initial velocity of 12 m/s. Find the momentum of the ball of dough halfway to its maximum height on the way up. and A 61 kg polevaulter … 
Physics
A 57.8 kg polevaulter falls from rest from a height of 5.4 m onto a foamrubber pad. The polevaulter comes to rest 0.25 s after landing on the pad. (a) Calculate the athlete's velocity just before reaching the pad. ______ m/s downward … 
Physics
A 59 kg polevaulter falls from rest from a height of 5.5 m onto a foam rubber pad. The polevaulter comes to rest 0.39 s after landing on the pad. a. Calculate the athlete's velocity just before reaching the pad. b. Calculate the … 
Physics
A 55 kg pole vaulter falls from rest from a height of 5m onto a foam rubber pad. The pole vaulter comes to rest .3s after landing on the pad. A) calculate the athlete's velocity just before reaching the pad B) calculate the constant … 
physics
A 85 kg polevaulter falls from rest from a height of 6.4 m onto a foamrubber pad. The polevaulter comes to rest 0.48 s after landing on the pad. (a) Calculate the athlete's velocity just before reaching the pad. m/s downward (b) …