An 80.0 kg jogger starts from rest and runs uphill into a stiff breeze. At the t

Question

An 80.0 kg jogger starts from rest and runs uphill into a stiff breeze. At the top of the hill the jogger has done the work wnc1=1.80*10^4J, air resistance has done the work Wnc2=-4420J, and the jogger's speed is 3.50 m/s find the height of the hill....

This is a problem worked out in the book but im having a hard time with Inital and final potential and kinetic energies

The Initial mechanical energy, Ei=ui+ki= 0+0=0 Why are these values zero?

Ef=uf+kf=mgh+1/2mv^2 again i would think that final kinetic would be zero because if he stops at the top of the hill it would be changed back to potential

HELP the rest of the problem I GET!!

Explanation / Answer

well everyone else has answered the numbers, but your question. it says his speed is 3.5m/s which means he was still moving. He never stopped he just came incontact with air resistance.

if the object can fall it has potiential

if the object is in motion it has kinetic

if the object is put in or out of motion by a spring you have Potiential of a spring

if the object has anything done to speed up or slow down such as friction, it has work done to it

hope that helps.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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