<p>Well, I was really enjoying this Physics I course until we had our first test today. I am getting A's and B's on all the labs and homework assignments but this first test was unreal.</p>
<p>I talked to some people after class and we made a lot of the same mistakes, I felt like a lot of us got only about half of the problems right </p>
<p>This is a summer class at a local community college, 95% of our students are Engineering students at ISU, some people are doing well but I think at least half of the class really struggled with this first test.</p>
<p>Keep going, learn from your mistakes and try to do better on the 2nd test or drop the class? Dropping is like the very last resort for me but at the same time, I like to be realistic.</p>
<p>We have a study group that meets almost every night for at least 3 hours- it has been very helpful but apparently not helpful enough. </p>
<p>Just trying to find a way to better deal with this class because it is really stressing me out.</p>
<p>I got a 27 on my first physics I test, then went off to make 80, 100, and 83 on the next exams, thanks to the curve I made an A on the class. We could drop one test though…</p>
<p>To do physics justice you really have to do a lot of problems. Physics 1, mechanics and heat, requires as much work as calculus 1, if not more. Being that most folks dont do the required work the curve is pretty good.You may be able to pass with a 50%, consult the instructor.</p>
<p>Thanks for your responses. I talked to the people in my study group and we are going to stick it out. Hopefully, our effort will pay off in the end.</p>
<p>If you don’t mind me asking, what were some of the specific mistakes made?</p>
<p>Well- we had one of those problems when you throw a ball upwards with an initial velocity, and we are asked to find the time it takes for the ball to reach halfway between initial position and the highest point where V=0. </p>
<p>Me and my friend used (Vf=Vi + at) to find the time it took for the ball to travel between the initial position and the highest point(where Vf=0) and divided it by 2, but apparently that is wrong.</p>
<p>This girl did the problem differently and got a different time for answer.</p>
<p>Then, a lot of us did not remember how to find the derivative of 3/t^2, so we were supposed to take the 2nd derivative of a position function x(t)= 6t^2 + 3/t^2 to find acceleration at t=3</p>
<p>Pretty simple if you remember how to derive 3/t^2. I ended up using the quotient rule twice and got a really nasty function at the end 
Anyways, I could go on and on… I am really frustrated</p>
<p>Honestly, that sounds like a completely fair problem, as most problems on exams are if your teacher is at least somewhat reasonable. It’s quite tricky, and I think you’d be better off integrating up to position, finding Xmax, and then solving for t at Xmax/2. </p>
<p>Nevertheless, the point is that both of these problems are quite doable, and that means the problem is a lack of proper preparation. I’ll assume that you did study for this test - it sounds like you did. The problem then is that you really didn’t learn how to understand these problems.
Do practice problems, and know your basic calculus. Most problems can be figured out from just a few ideas in physics. You should still be able to do well enough for the rest of the class, although it gets harder - spinning stuff is actually legitimately difficult.</p>
<p>Oh and half the class will always do badly, in every class (except maybe those full of only top tier students). That’s no excuse.</p>
<p>Math skills are the key to success in intro physics. There is only one important equation for all kinematics problems if you are competent with the calculus used to derive other forms.</p>
<p>The example problem you describe is not trivial but not unreasonably difficult either. This is how I would solve it:</p>
<ol>
<li>Objective: the time to ascend halfway to the highest point. We can find this time if we know the distance traveled since we already know the acceleration and initial velocity.</li>
<li>Objective: half of the maximum height. We can find the maximum height if we know the time taken to get there.</li>
<li>Objective: time to the maximum height. We can find this from the change in velocity and the constant acceleration, as you did already.</li>
</ol>
<p>Do you see the way I worked backwards to find relationships between unknown and known quantities? That’s the way to solve physics problems.</p>
<p>This is not a forum for homework but if you are having trouble studying a specific concept before an exam I would be happy to try to help via PM. Good luck!</p>
<p>I am not sure about the content and progress of these MOOCs and whether they would match yours. But worth to check them out:</p>
<p>Coursers: Introductory Physics I with Laboratory </p>
<p>edX: Mechanics ReView
<a href=“https://www.edx.org/course/mit/8-mrevx/mechanics-review/748[/url]”>https://www.edx.org/course/mit/8-mrevx/mechanics-review/748</a></p>
<p>In general, I don’t think there is a course that difficult for your degree that you couldn’t overcome. You have your teacher, tutor, classmates, intelligence, etc. All you need is time and effort, and not giving up. I am sure there will be other things more difficult in your life than this. So don’t develop the habit of quitting. There is no turning back on something like this unless you couldn’t be an engineer.</p>
<p>I think the main cause of your problem was not knowing the material to allow you to do the problem:
</p>
<p>
Pretty simple, if you knew how to take a derivative. Next time, know how to take a derivative, especially when you’re taking a test that involves the relation between position, velocity, and acceleration (which are derivatives of each other, respectively.)</p>
<p>I haven’t taken physics with calculus as of yet, but I can understand how to do the problem from a calculus point of view. </p>
<p>The algebraic way to do it is just to break the problem into components, use the time as a “medium” between the x and y components and then find the height in the y component. This is using: deltax=1/2at^2+vit</p>
<p>The great thing about physics is it’s like a puzzle. You’re given some information. You have some equations and you have I find out how to use that little bit of information with those equations to get your answer. It’s pretty fun rearranging things. I strongly suggest you dig in deeper and to not give up! Really focus on the relationships present in certain problems because those relationships are key in solving the problems. </p>
<p>Don’t give up. Physics is fun!</p>