The Proof is Trivial physics edition?

Physics is not about proof. Physics is about using mathematics to model certain scenarios that play out in the real world. So the name would not be appropriate. Maybe a name like "problem solving for Physics".

Try this one

A block of mass 8 kg is resting on a slope of 30° to the horizontal. A force of 80 N is applied up the slope at an angle of 20° relative to the slope. Given the coefficient of kinetic friction is 0.5, what is the acceleration of the block up the slope?

Too easy, it's basically an M1 question. The point would be to make questions that are a bit harder but rely on the same knowledge base. Regardless, I got 0.253ms^-2? Up the slope.

It would be nice to have some more conceptual questions TBH but until I think of something:

Describe qualitatively what would happen if the 80N force was replaced by a 50N force acting at 50⁰ to the inclined plane.

Too easy, it's basically an M1 question. The point would be to make questions that are a bit harder but rely on the same knowledge base. Regardless, I got 0.253ms^-2? Up the slope.

Where is your working? God knows how you got there

Actually that's not the answer Try again

I would say qualitatively, without any calculations, that the block would remain stationary on the slope


Out of interest are you doing A level or are you a physics student?

EDIT:
This question requires a bit more thought than appears at first glance

Woops, did that too fast. Actual working should have looked like this:
Resolving perpendicular: $N=8gcos(30)-80sin(20)$
Resolving parallel: $F_r=80cos(20)-8gsin(30)-0.5N$

Which gives 1.96ms^-2 after F=ma.

I still think that's too easy, and I'm doing A level.

Still wrong... answer is 1.78 ms^-2

You sure? What value of g are you using?

Oh right, I'm guessing you're using g= 9.81?

Oh right, I'm guessing you're using g= 9.81?

I used 9.8 because that's what we use in M1 I've just checked all three and you get your answer for g=10, 1.96 for g=9.8 and 1.95 for g=9.81.

Protip: use $g$ instead of $10$ or $9.81$. Then in your final answer, give $f(g) \approx f(9.81)$ or whatever.

This was a rather number-y question. $a=10(cos(20)+\mu sin(20)-g(sin(30)+\mu cos(30))$ didn't really seem right.