hey guys this is Alan with Bothell stem coach and we're doing the next free response question from the AP physics 1 2017 exam so this is question number for a physics classes acid is on a low friction slide that will launch a block horizontally from the top of a lab table teams wanted to assemble the slide shown above and use identical blocks wanted to both slide started the same height D above the table top okay however teams whose table is Laurent Team one stable to compensate for the lower table team two constructs the right into the slide to rise above the table attached to the block leaves the slide horizontally at the same height H above the floor as team Ones block both blocks are released from the top at the respective slides to block loan to Lam in the same distance okay so they they both leave at the same height right and presumably they don't lose any energy along the way because it's frictionless well we'll say low friction but but what's gonna happen is block so what you do when there's no frictional energy losses conservation of energy all of this height this potential energy here gets converted to kinetic energy but this height and this like he is only D minus H above where they finish out so he has less potential energy than this guy so this guy's gonna come out with a lower velocity like less potential energies getting converted so no block one lands further because it starts with more more potential energy okay that part's pretty easy and another experiment teams wanted to use the tables and low friction slides with the same height however the two slides of different shape is shown below both blocks are loose from rest there's a witch block if either lands further from the respective table same distance because here is the same distance because again its energy conversion is converting the potential energy to kinetic energy so it'd be about the same the same potential energy is converted into kinetic energy so it's the same same amount of potential energy and that implies same velocity right because the kinetic energy is one-half MV squared if it has the same kinetic energy as the same velocity it has the same velocity then they'll both go the same distance because they're launched horizontally at the same height which block if either hits the floor first they hit the at the same time they at the same time because they both start like when they're launched when launched when launched both start with no vertical velocity no initial versus vertical velocity and they start at the same height so they're both gonna you know the only thing that governs how long it stays in the air is how is the effect of gravity you know causing it to fall to the ground since they both start with no vertical velocity when they're launched then they'll don't know fall at the same rate okay so that was a really qualitative questions kind of weird let's take a look at the scoring guidelines for that one question for answer is no the amount of potential energy cover is different for the two blocks potential is proportional to change in height which is smaller for block two therefore okay so yeah that's what we reasoned out the two blocks land the same distance because the same change in potential energy kinetic energy and correct answer is block one wait what was the question oh they're saying from oh oh oh I see I see what they're saying is that block to will because they release him at the same time block to while they'll start off at the same velocity here by the time he get like this guys faster cuz he's just steeper like he gets from here to here faster and then this guy gets from here to here however the actual fall time is the same it's just from here to off that's a tricky question I was wondering why I was thinking that it was a little off on that one that is true I didn't think about that this would slide faster than this one um by the end they'll have the same velocity but this one would just get there faster alright okay okay fair enough fair enough I didn't get that one so it's two points yeah okay didn't get that right okay well thanks for watching um sorry I kind of messed that one up the last two points in that one so disappointing but I hope it made sense and I hope you learned something from watching me do the problem and this just goes to show I don't look at the solution if I do the problem clearly otherwise I would have gotten that right so thanks for watching please leave a comment like or subscribe and I will see you in the next video where we'll do the final free response question thanks