Go Back   Physics Help Forum > High School and Pre-University Physics Help > Kinematics and Dynamics

Kinematics and Dynamics Kinematics and Dynamics Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old May 11th 2009, 07:32 AM   #1
Junior Member
 
Join Date: May 2009
Posts: 3
Office argument needs settling

Good afternoon

Bit of a silly one but needs sorting!

I am currently having an argument with one of my colleagues at work and would appreciate it if someone could settle it!!

Scenario:
I'm stood at the top of the Eifel Tower, I have a golf ball in one hand and one in a cannon (pointing horizontally) I drop the golf ball by hand and simultaneously fire the cannon......which will hit the ground first?!....I am adamant that the 'cannon golf ball' will take longer to reach the ground. Please could someone solve this argument.

Regards
congerball is offline   Reply With Quote
Old May 11th 2009, 10:09 AM   #2
Physics Team
 
Join Date: Feb 2009
Location: India
Posts: 365
In absence of air the two balls will take same time.
I am not sure about what happens in presence of air.
Parvez is offline   Reply With Quote
Old May 11th 2009, 07:58 PM   #3
Senior Member
 
Join Date: Feb 2009
Location: Singapore
Posts: 206
they should hit the ground at the same time
arze is offline   Reply With Quote
Old May 12th 2009, 07:23 AM   #4
Junior Member
 
Join Date: May 2009
Posts: 3
Thankyou for your replies
congerball is offline   Reply With Quote
Old May 12th 2009, 10:33 AM   #5
Physics Team
 
Join Date: Feb 2009
Posts: 1,425
In the presence of air both balls will experience a drag / frictional force which is generally proprtional to the square of the velocity.
Since the vertical motion of both the balls is identical and so are their surfaces, both will experience identical retarding forces, so both will take the same time. However the time taken will be larger than in the case without air, as the net acceleration is now < g.
As far as the horizontal motion goes, it should cover the same distance i think because though the time taken is larger, the horz velocity also decreases and both depend on v^2. Vertically the resistive force increases with time and horizontally it decreases with time.
physicsquest is offline   Reply With Quote
Old May 13th 2009, 03:43 AM   #6
Junior Member
 
Join Date: May 2009
Posts: 1
Golf Ball

The golf ball fired out of the cannon ( with air present ) will take slightly longer due to the fact the it has to travel through more air and therefore the resistance will cause more lag than the ball dropped vertically. Hope that answers your question.
mr physics is offline   Reply With Quote
Old May 13th 2009, 07:06 AM   #7
Junior Member
 
Join Date: May 2009
Posts: 1
Who won the arguement then Congerball?
Creation is offline   Reply With Quote
Old May 13th 2009, 11:43 AM   #8
Physics Team
 
Join Date: Feb 2009
Posts: 1,425
The golf ball fired out of the cannon ( with air present ) will take slightly longer due to the fact the it has to travel through more air and therefore the resistance will cause more lag than the ball dropped vertically. Hope that answers your question.

Since the vertical displacement is the same, the time taken will be the same.
physicsquest is offline   Reply With Quote
Old May 14th 2009, 03:43 AM   #9
Junior Member
 
Join Date: May 2009
Posts: 3
Once again thanks for the replies.....I won the argument!!
congerball is offline   Reply With Quote
Old May 14th 2009, 10:19 AM   #10
Physics Team
 
Join Date: Feb 2009
Posts: 1,425
But maybe physics lost!
physicsquest is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Kinematics and Dynamics

Tags
argument, office, settling



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Why is Maxwell's demon a significant argument? kiwiheretic Thermodynamics and Fluid Mechanics 6 Jul 14th 2016 02:20 AM


Facebook Twitter Google+ RSS Feed