Recent content by TheBigDig

Thank you very much for these answers, I will consider change in KE instead

Taking v = 2m/s, u=0m/s and s = 15m, we get ##a=0.13m/s^2## ##F_g = mg = 100(9.8) = 980N## Since there's no vertical acceleration, the normal force is equal to the weight ##N = 980N## ##f = \mu_k N = 0.05(980) = 49N## ##F_{net} = ma = 100(0.13) = 13N## ##F_{app} = F_{net}+f = 62N## My...

Sorry yes of course. The normal force is perpendicular to the surface and the car will roll backward. I believe the model should correspond to this

For part 1, I got ## tan \alpha = 1/30 ## ##\alpha = 1.9^{\circ}## ##mgcos(1.9) = 10774N## I'm a little thrown off by the second part. Are we supposed to assume that in the absence of friction, F = N and then substitute F = ma to solve for this?

Sorry about that, I changed the post to reflect your corrections. ##l## is for the length of the rod and S is the length of the pendulum now. Thanks for the advice. I'll try giving that a go

I have been given an answer for this but I am struggling to get to that point $$ANS = 0.430\, kg \cdot m^2$$ So I thought using the moment of inertia of a compound pendulum might work where ##I_{rod} = \frac{ml^2}{12}## and ##I_{disc} = \frac{mR^2}{2}## (##l## is the length of the rod and ##R##...

Hi there! Thank you so much for your help. As it turns out we have covered this before but I didn't consider that these manipulations could be performed when it was three variables taken from the same data set if you understand me. I thought it only applied to normal variables with different...

I've found part (i) by calculating the z-score for 40 $$Z = \frac {40- 50} {15} = -0.67$$ $$N(-0.67) = 1- N(0.67) $$ $$1- N(0.67) = 1-0.7486 = 0.2514$$ But parts (ii) and (iii) are confusing me. I have answers provided by my professor that say the mean and std deviation for (ii) and (iii) are...

Okay yes, this definitely seems like something I need to read up on. Our instructor is a little handwavy at the moment saying we'll come across these concepts later but I'm one of those people who needs to understand each element. Thank you as well. Yes I think it is missing that. I found it...

Apologies if this isn't the right forum for this. In my stats homework we have to prove that the expected value of aX and bY is aE[X]+bE[Y] where X and Y are random variables and a and b are constants. I have come across this proof but I'm a little rusty with summations. How is the jump from the...

Sorry, it was from notes given by my lecturer. I looked up the reference material for the course but couldn't find any reference to it. Thanks for this discussion and explanation guys, really improved my understanding. I will take a look at this paper.

I've come across this alternative formulation of Planck's Law which links the number density to energy gap n(E) = \frac{2\pi}{c^2 h^3} \frac{E^2}{exp\big(\frac{E-\mu}{k_BT})-1} I've tried visualising this relation and I imagine it will look similar to the spectral density relation but I'm just...

So far the best I've been able to come up with is to use ##\vec{B} = \mu_0 \vec{H}## which gives me i_c = H 2\pi r j_c = \frac{H 2\pi r}{\pi r^2} = \frac{2H}{r} \therefore B = \mu_0 \frac{r j_c}{2} I'm fairly confident this is just terrible math and physics on my behalf but I'm struggling to...

So I worked out the first part and obtained ##E_1 = 478.8MeV##, ##E_2 = 459.4MeV## and ##p = 0.49 MeV/c## but I can't quite wrap my head around the second part. Normally, I'd use the equation for s but I'm confused since I don't know the angle between the gamma rays.

Forgive me for being dense but what'll that imply for the force?