Hovercraft B/C

Test your knowledge of various Science Olympiad events.
Locked
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Hovercraft B/C

Post by UTF-8 U+6211 U+662F »

IcsTam wrote:What is the difference between turbulent and laminar flow? How does Reynold's number pertain to these concepts? What value (or range of values) distinguishes between turbulent and laminar flow?
In laminar flow, the molecules in the fluid are assumed to not cross over each other's paths, i.e. not have turbulence. Reynold's number relates to the speed at which a fluid is no longer reasonably considered laminar. When Re < 2300, laminar flow occurs, and when Re > 2600, turbulent flow occurs.
IcsTam
Member
Member
Posts: 60
Joined: March 1st, 2017, 5:09 pm
Division: Grad
State: PA
Has thanked: 0
Been thanked: 0

Re: Hovercraft B/C

Post by IcsTam »

UTF-8 U+6211 U+662F wrote:
IcsTam wrote:What is the difference between turbulent and laminar flow? How does Reynold's number pertain to these concepts? What value (or range of values) distinguishes between turbulent and laminar flow?
In laminar flow, the molecules in the fluid are assumed to not cross over each other's paths, i.e. not have turbulence. Reynold's number relates to the speed at which a fluid is no longer reasonably considered laminar. When Re < 2300, laminar flow occurs, and when Re > 2600, turbulent flow occurs.
Correct, your turn!
Penncrest ‘18
UPenn ‘22
SOUP Sounds Director ‘19, ‘20
PM me about UPenn, Physics, or anything college or SciOly related!
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Hovercraft B/C

Post by UTF-8 U+6211 U+662F »

What was the original formulation of Newton's Second Law that takes into account changes in mass?
User avatar
Justin72835
Member
Member
Posts: 175
Joined: June 25th, 2017, 7:06 am
Division: Grad
State: TX
Has thanked: 0
Been thanked: 1 time

Re: Hovercraft B/C

Post by Justin72835 »

UTF-8 U+6211 U+662F wrote:What was the original formulation of Newton's Second Law that takes into account changes in mass?


Interestingly, Newton was referring to momentum when formulating this law and not force :D
"The fault, dear Brutus, is not in our stars,
But in ourselves, that we are underlings."


University of Texas at Austin '23
Seven Lakes High School '19
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Hovercraft B/C

Post by UTF-8 U+6211 U+662F »

Justin72835 wrote:
UTF-8 U+6211 U+662F wrote:What was the original formulation of Newton's Second Law that takes into account changes in mass?


Interestingly, Newton was referring to momentum when formulating this law and not force :D
Yep, your turn!
User avatar
Justin72835
Member
Member
Posts: 175
Joined: June 25th, 2017, 7:06 am
Division: Grad
State: TX
Has thanked: 0
Been thanked: 1 time

Re: Hovercraft B/C

Post by Justin72835 »

UTF-8 U+6211 U+662F wrote:
Justin72835 wrote:
UTF-8 U+6211 U+662F wrote:What was the original formulation of Newton's Second Law that takes into account changes in mass?


Interestingly, Newton was referring to momentum when formulating this law and not force :D
Yep, your turn!
A large cylindrical tank with height 10 meters and radius 2.5 meters is filled up entirely with water. A circular hole with a radius of 10 cm is punctured underneath the tank. Given that the top of the tank is open to the atmosphere, how long will it take for the entire volume of water to flow out of the tank (assuming no change in flow rate due to changing height?
Last edited by Justin72835 on March 12th, 2018, 8:44 pm, edited 1 time in total.
"The fault, dear Brutus, is not in our stars,
But in ourselves, that we are underlings."


University of Texas at Austin '23
Seven Lakes High School '19
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Hovercraft B/C

Post by UTF-8 U+6211 U+662F »

Justin72835 wrote:
UTF-8 U+6211 U+662F wrote:
Justin72835 wrote:


Interestingly, Newton was referring to momentum when formulating this law and not force :D
Yep, your turn!
A large cylindrical tank with height 10 meters and radius 2.5 meters is filled up entirely with water. A circular hole with a radius of 10 cm is punctured underneath the tank. Given that the top of the tank is open to the atmosphere, how long will it take for the entire volume of water to flow out of the tank?




User avatar
Justin72835
Member
Member
Posts: 175
Joined: June 25th, 2017, 7:06 am
Division: Grad
State: TX
Has thanked: 0
Been thanked: 1 time

Re: Hovercraft B/C

Post by Justin72835 »

UTF-8 U+6211 U+662F wrote:
Justin72835 wrote:
UTF-8 U+6211 U+662F wrote: Yep, your turn!
A large cylindrical tank with height 10 meters and radius 2.5 meters is filled up entirely with water. A circular hole with a radius of 10 cm is punctured underneath the tank. Given that the top of the tank is open to the atmosphere, how long will it take for the entire volume of water to flow out of the tank?




I got [b]446 seconds[/b], which is basically half your answer. With that said, I think you made a mistake in your second line. Since you're multiplying both sides by two, the expression underneath the square root is g(20m) instead of g(5m). 

All your other work is correct though, so nice job! You can do the next one!
"The fault, dear Brutus, is not in our stars,
But in ourselves, that we are underlings."


University of Texas at Austin '23
Seven Lakes High School '19
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Hovercraft B/C

Post by UTF-8 U+6211 U+662F »

Oh whoops, haha.
Find the final speed of a 100 kg roller coaster car that has dropped 50 m (from rest), gone back up 30 m, dropped 60 m, gone back up 30 m, and then at that level been pushed for 5 seconds with a force of 50 Newtons.
MattChina
Member
Member
Posts: 225
Joined: February 12th, 2017, 8:06 am
Division: B
State: NY
Has thanked: 0
Been thanked: 0

Re: Hovercraft B/C

Post by MattChina »

UTF-8 U+6211 U+662F wrote:Oh whoops, haha.
Find the final speed of a 100 kg roller coaster car that has dropped 50 m (from rest), gone back up 30 m, dropped 60 m, gone back up 30 m, and then at that level been pushed for 5 seconds with a force of 50 Newtons.
2.5 m/s
2019 events: Water Quality, Battery Buggy, Elastic Launch Glider, Density Lab, Circuit Lab, Thermodynamics
R.C Murphy Co-Captain
Dank Memes Area Homeschool Team member
Locked

Return to “2018 Question Marathons”

Who is online

Users browsing this forum: No registered users and 3 guests