Wind Power B/C

Locked
User avatar
samlan16
Member
Member
Posts: 523
Joined: December 30th, 2013, 2:54 pm
Division: Grad
State: TN
Has thanked: 0
Been thanked: 0
Contact:

Wind Power B/C

Post by samlan16 » July 30th, 2015, 12:59 pm

This question marathon is for the 2015-16 event Wind Power, which involves a written portion about energy.

First question (I'll keep this simple): Suppose that you are shooting an arrow of mass 21 g from a height of 1.5 m at the bottom of a hill 9.42 meters tall. If you fire the arrow and it lands on top of the hill,

a) How much gravitational potential energy did the arrow gain?
b) What was the initial velocity of the arrow?
Remember, we are proud of every team that participated and you are all winners.

liberalartslover
Member
Member
Posts: 26
Joined: April 25th, 2015, 1:18 am
Division: C
State: CA
Has thanked: 0
Been thanked: 0

Re: Wind Power B/C

Post by liberalartslover » July 30th, 2015, 4:19 pm

a) 1.63 J
b) 12.5 m/s

User avatar
samlan16
Member
Member
Posts: 523
Joined: December 30th, 2013, 2:54 pm
Division: Grad
State: TN
Has thanked: 0
Been thanked: 0
Contact:

Re: Wind Power B/C

Post by samlan16 » July 30th, 2015, 5:55 pm

liberalartslover wrote:
a) 1.63 J
b) 12.5 m/s
A is wrong. I'll let you figure out why.
Remember, we are proud of every team that participated and you are all winners.

liberalartslover
Member
Member
Posts: 26
Joined: April 25th, 2015, 1:18 am
Division: C
State: CA
Has thanked: 0
Been thanked: 0

Re: Wind Power B/C

Post by liberalartslover » August 15th, 2015, 2:59 pm

Really how?
(9.42-1.5)*9.8*.021 = 1.63

Also if part B is 12.5 then part A has to be 1.63 because of conservation of energy.

User avatar
samlan16
Member
Member
Posts: 523
Joined: December 30th, 2013, 2:54 pm
Division: Grad
State: TN
Has thanked: 0
Been thanked: 0
Contact:

Re: Wind Power B/C

Post by samlan16 » August 15th, 2015, 3:36 pm

liberalartslover wrote:Really how?
(9.42-1.5)*9.8*.021 = 1.63

Also if part B is 12.5 then part A has to be 1.63 because of conservation of energy.
Sig figs.
Remember, we are proud of every team that participated and you are all winners.

liberalartslover
Member
Member
Posts: 26
Joined: April 25th, 2015, 1:18 am
Division: C
State: CA
Has thanked: 0
Been thanked: 0

Re: Wind Power B/C

Post by liberalartslover » August 15th, 2015, 4:29 pm

*sigh*

1.6 and 13 then?

User avatar
samlan16
Member
Member
Posts: 523
Joined: December 30th, 2013, 2:54 pm
Division: Grad
State: TN
Has thanked: 0
Been thanked: 0
Contact:

Re: Wind Power B/C

Post by samlan16 » August 15th, 2015, 6:47 pm

Correct.
Remember, we are proud of every team that participated and you are all winners.

Locked

Return to “2015 Question Marathons”

Who is online

Users browsing this forum: No registered users and 4 guests