<p>i hope the curve is nicer this time…it was harder than the practice tests i did…</p>
<p>I think I guessed for the experiment apparatus one…or I left it blank lol I was going to choose balance and something else though…i thought you needed to know the mass, but that was a guess.</p>
<p>Why would the horizontally moving ball move SE after collision? I still don’t quite understand lol The previous reasoning was that the vertically moving ball didnt have a horizontal velocity to cancel out, but then that would mean the horizontally moving ball wouldn’t have a vertical velocity to cancel the vertical ball…kinda confusing, i know haha</p>
<p>It is SE because the balls have different masses. So, to conserve momentum, it can’t travel in negative y-direction alone, it must be SE.</p>
<p>oh did it say different masses?? I thought it was just “two marbles” or something…or was that a different question haha</p>
<p>yeah, i think it did say different masses. it was written in a small paragraph.</p>
<p>the thing with this test was that there really wasn’t enough time for me…so I had to skim through questions and probably missed out on things like “different masses”…sigh…so sad</p>
<p>agreed…i missed out on a few questions, too.</p>
<p>all you needed to find acceleration of the system was a balance. if you know their weights then you can just use newton’s laws of motion.</p>
<p>^But the frictional force was not given. So, how would only knowing the masses of the block help?</p>
<p>it was frictionless</p>
<p>The left block was on an inclined plane, right? Then was the angle of inclination also given?</p>
<p>no, i think it was on a horizontal, flat plane</p>
<p>If it was a horizontal AND frictionless plane then one wouldn’t even need anything to find out the acceleration because then evidently a=g. So, I believe that the plane wasn’t frictionless and the force of friction wasn’t given and thus, we couldn’t calculate the acceleration of the right block just by finding out the mass.</p>
<p>that is conceptually flawed- F=ma, masses were m1 and m2, so a= m1g/(m1+m2)…assuming m2 was on the horizontal plane…that was my reasoning…</p>
<p>Well, that’s the thing, if m2 was on a frictionless plane then m2 would provide no resistance at all; hence, m1 will continue to fall like it normally would because m2,without friction, will not provide kind hindrance whatsoever.</p>
<p>even if it’s frictionless.</p>
<p>say m1 is the one on the table, m2 is hanging.</p>
<p>m2g-T =m2a
T=m1a
so
m2g-m1a=m2a
m2g/(m2+m1) = a</p>
<p>^So all you would need is a balance to measure the masses right?</p>
<p>Now, where did T come from? Tension is a force related to the stretching of an object. The string shouldn’t even stretch because on one end you have a free falling object(m2) on the other end you have absolutely nothing to hold on to (because there is no friction for m1 and it will have no effect as it’ll provide no resistance!). Tension can’t arise by the action of only 1 force. So, basically string will also fall along with the block m1 and there won’t be any stretch in the string.</p>
<p>if it was frictionless then yes you would only need a balance.
i’m not certain that it was frictionless, however…</p>
<p>yes, all you need is a balance</p>