Recent content by dh743

Thanks for the reply. So you've multiplied everything by di, but what does that actually show? As in why would you do it? Also, why isn't the gradient simply 1/do since (di/do)/di = 1/do?

Homework Statement Following data recorded: Di (distance image to lens) 6.0 8.0 10.0 12.0 14.0 Magnification 0.2 0.6 1.0 1.4 1.8 Graph magnification against di and use the graph to find the focal length of the lens. Homework Equations...

Thanks for all your help, but I still can't get it to a point where I only have one unknown - I always end up with both q and r as unknowns. And what do the subscript 12 and 13 mean in your above equation?

Ok letting 5 microC be y and 8 microC be z, this is I've ended up with: Ey=\frac{kq}{r2} Ez=\frac{kq}{(0.9-r)2} Eq = \frac{k(5microC}{r2} + \frac{k(8 microC}{(0.9-r)2} I can't solve them because I always end up with 2 unknowns so I must have made a mistake somewhere.

Homework Statement A 4microC point charge is placed at the coordinate origin. Two other point charges are placed on the x axis: q1 at x=30cm and q2 at x=50cm. Find the magnitude and sign of q1 and q2 if the net force on each of the three charges is zero. Homework Equations...

That makes sense, but how do I now arrange it to avoid having 2 unknowns?

Yeah you're right, it does mean the net force on each charge is zero. How did you get the answer though?

Homework Statement Two point charges are placed on the x axis: +5 microC charge at x=0 and +8 microC charge at x=0.9m. Where on the x-axis can a third charge be placed so that the net charge on all three charges is zero? Determine the magnitude of the third charge. Homework Equations...

Homework Statement Find the derivative of y= (2x2 + 1) x1/2 Homework Equations Product RuleThe Attempt at a Solution After differentiating, I eventually get stuck at: \frac{4x3/2+2x2+1}{2\sqrt{x}} The given solution is \frac{10x2+1}{2\sqrt{x}}

Thank you it makes sense now.

Thanks for replying and I've added some brackets (the question didn't have any). Wouldn't the numerator be 2^{n+4}- 2^{n+1}?

Homework Statement Simplify: (2n+4 - 2 x 2n) / (2n+2 x 4)Homework Equations N/AThe Attempt at a Solution (2n+4 - 2n+1) / (2n+4) Unsure where to go from here, but the given answer is 7/8 Thanks for any help

Thanks for your help but i ended up with the correct answer but negative (-1.8). Would this be correct in this situation? I would have thought an increase in mass (the object) would mean an increase in momentum.

the answer I've got is 1.8

Homework Statement A 2.4kg cart is moving with a constant speed of 2m/s along a smooth horizontal plane when a 1.5kg object is dropped vertically onto it. What is the change in momentum of the trolley? Homework Equations p=mv \Deltap=p final - p initial The Attempt at a Solution...