Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 12th, 2013, 7:22 pm
by fantasyfan
A first class lever(to amplify the force), two third class levers (to lower the wedges) and two wedges (to clip the nail)
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 12th, 2013, 7:42 pm
by jjetpack
fantasyfan wrote:A first class lever(to amplify the force), two third class levers (to lower the wedges) and two wedges (to clip the nail)
Wait, wouldn't it be composed of a second class lever (imput on the handle, output on the top wedge, with the cylinder as the fulcrum) and only one 3rd class lever (the bottom wedge usually doesn't move). And then of course two wedges.
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 12th, 2013, 8:52 pm
by chinesesushi
jjetpack wrote:
fantasyfan wrote:A first class lever(to amplify the force), two third class levers (to lower the wedges) and two wedges (to clip the nail)
Wait, wouldn't it be composed of a second class lever (imput on the handle, output on the top wedge, with the cylinder as the fulcrum) and only one 3rd class lever (the bottom wedge usually doesn't move). And then of course two wedges.
jjetpack is correct. The lever which you press down upon is a 2nd class lever which exerts a force on a 3rd class lever. Your turn.
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 12th, 2013, 9:27 pm
by jjetpack
Ok, here goes nothing.
A certain single-helical screw has a head whose diameter is 1/2" and a pitch of 1/10". If you apply 100N to turn the screw (just rotational, no downward force) and the screw drives into the wood below with 141N, what is the screw's efficiency?
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 13th, 2013, 2:20 pm
by chinesesushi
jjetpack wrote:Ok, here goes nothing.
A certain single-helical screw has a head whose diameter is 1/2" and a pitch of 1/10". If you apply 100N to turn the screw (just rotational, no downward force) and the screw drives into the wood below with 141N, what is the screw's efficiency?
8.98%
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 13th, 2013, 7:59 pm
by jjetpack
Correct. Screws have a LOT of friction...
Your turn, chinesesushi
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: November 13th, 2013, 8:08 pm
by chinesesushi
Draw a compound machine that consists of at least three different types of simple machines and a 1st class and 2nd class lever that has a mechanical advantage that totals to 210.
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: December 20th, 2013, 8:15 am
by chinesesushi
It's been too long since we had a question for this event. Now it's located underneath all the other marathons. So...
Which scientist/engineer was the first to derive the mechanical advantage of an inclined plane and in what year did he do it?
Re: Simple Machines B/Compound Machines C Question Marathon
Posted: January 1st, 2014, 1:17 pm
by helicpters_rule
chinesesushi wrote:It's been too long since we had a question for this event. Now it's located underneath all the other marathons. So...
Which scientist/engineer was the first to derive the mechanical advantage of an inclined plane and in what year did he do it?
1586, Flemish engineer Simon Stevin (Stevinus) its copyed from wikipedia
Re: Simple Machines B/Compound Machines C Question Marathon
