Recent content by Clairefucious

Hey, don't stress! All you need is the angle. The static coefficient of friction is a ratio of the component of the force along the slope and the component of the force normal to the slope. It is independent of mass of object and material of object and slope. Consider the force trying to...

What about your solution doesn't work? Are you using A = \pi (0.1m)^2 \epsilon_{0} = 8.854 \times 10^{-12} F/m C = \frac{\epsilon _{0} A}{0.0099m} and Q = C \times 15V ? These are the equations you listed in your relevant equations section, and they should work!

Energy is conserved. Kinetic energy in an elastic collision (where there is no conversion to any other sort of energy) remains the same.

That last formula was meant to be a = \frac{d^{2}x}{dt^{2}}

Comments on the chain rule: \frac{dy}{dt} may be written as \frac{dy}{dt}\frac{dx}{dx}. Rearranging we get \frac{dy}{dx}\frac{dx}{dt}. Does this make a bit more sense by writing in the middle step? For acceleration a = \frac{dv}{dt} and velocity is v \frac{dx}{dt}. We put these together by...

Acceleration due to gravity: a = -9.8m/s2 note the minus sign! The reason why this is negative: the flea is jumping up (positive direction), acceleration is acting down (negative direction as it is opposite to the direction of the jump) This cancels out your problem of negative...

I should just mention that time will be a function of the v0y. When you use this time in the equation for the x-direction velocity you'll end up with something like v0x * v0y = number. Then just use what you know about the angles to get the answer.

A few points you may find useful, for the full length problem 1) the jumper 'lands' - this means that at the end of the jump the y displacement is zero as she returns to the ground (y = 0) 2) the point above means that the final velocity in the y-direction must be equal in magnitude to the...

The equation v = x/t is for constant velocities only, ie a = 0. So using it in this question is not going to help. You are looking for the point where the stones cross - at this point they will have the same displacement from the ground and will have traveled for the same length of time. Use...

Yes, you do want something like tan(angle) = vx / vy. This gives you the angle between your vector and the vertical direction (the wall is vertical).

Then don't use final time in the acceleration equation! If acceleration is a constant, you can calculate it over any time interval.

hmm, I'm not sure how to represent matrices in this window. I have a stab at helping out anyway. This is a general formula. | percentage A | |amount of A | | | | | | percentage B | . |amount of B | = pA*aA + pB*aB + pC*aC |...

In these sorts of problems I find it useful to draw of diagram of the vectors. You know that the sum of all the x- and y-velocity vectors before and after the collison are equal which gives you the following options: y-velocity: uf*sin(phi) = - vf*sin(theta)...

Hey! Has anyone else heard of filaments of galaxies? Apparently galaxies fall onto galaxy clusters by first falling onto 'strings of galaxies' that feed the accretion. These filaments are supposed to connect galaxy clusters that are very close spatially. I think this has something to do with...

The ball has to have SOME initial speed greater than zero because it is traveling upwards. This is in the opposite direction to the acceleration due to gravity which is pulling the ball down and reducing the speed of the ball. The maximum height that the ball reaches is when the ball has...