
1  



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

2  A parachute jumps out of a plane with an intitial velocity of 3 m/s. The person drops 400 m when her parachute begins to open. The parachute takes 50 m to open and reduce her speed to 8 m/s. Which law of themodynamics is used to find the force of the parachute. 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

3  At Wintergreen ski resort, a snowboarder starts at 3 m/s at the top of a hill. She is traveling 25 m/s when she reaches the bottom of the hill. Neglecting friction which law of themodynamics is used to find the vertical height of the hill? 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

4  On a playground, a child sits in a swing waiting to be pushed. The dad pulls the child back and up 1.4 meters higher than the lowest point on the swing. The parent lets the swing go from rest. Which law of themodynamics is used to find the velocity whenthe child is at the bottom of the swinging motion? 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

5  A 968 kg dragster races down a 402 m long track in. The dragster starts from rest. At the end of the track a parachute opens and bring the car to a rest in 305 m with a 54,610 N force. Which law of themodynamics is used to find the velocity at the end of the track? 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

6  Which law of themodynamics would be used to find the velocity at location "B?" 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

7  Which law of themodynamics would be used to find the velocity at location "C" by comparing the energies between loacions "B" and "C?" 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 

8  Which law of themodynamics would be used to find the velocity at location "C" by comparing the energies between loacions "C" and "D?" 



1st Law (All mechanical energy is conserved.) E_{FINAL} = E_{INITIAL} 



2nd Law (All mechanical energy is not conserved ...but the difference can be accounted for by "work.") W = (E_{FINAL})  (E_{INITIAL}) 
