Recent content by m2287

does than not just give you wd = f* d im very confused about how to prove this!

wd= ma * d ?

that if you move an object around and place it back in its original position no energy is lost?

Homework Statement If a force on an object is always directed along a line from the object to a given point, and the magnitude of the force depends only on the distance of the object from the point, the force is said to be a central force. Show that any central force is a conservative force...

thanks a lot for your help, i think i have it now :D!

ok so i get: @ y(t) = 0, t = 0.17v0 putting that into x(t) = v0cos45t x(t) = v0 * 0.525* 0.17v0 x(t) = 0.0893v0^2 does this look right?

so for y(t) i get y(t) = 0.5 * -10t^2 0 = -5t^2 0 = 0 surely putting y(t) as 0 gives you y when it has traveled no distance? :S!

ok so i get: x(t) = v0cos(theta)t + 0.5 * -10t^2 x(t) = v0cos(theta)t -5t^2 d(x)/d(t) = -v0sin(theta)t - 10t d(x)/d(t) = -v0*0.525t - 10t @ d(x)/d(t) = 0 ----> 0 = -v0*0.525t - 10t v0 = -10t/0.525t v0 = -19 surely this should be positive!?

i can do differentiation but i don't know the horizontal expression of a projectile? so you mean the s u v a t equations? like s = ut + 0.5 at^2

with those equations, should you put them together to get a y=mx+c styled equation? i get y = x^2 and then go from there maybe?

Homework Statement the initial speed of a projectile is v0. what angle of projection theta makes its horizontal range R a maximum? what is the maximm horizontal range? Homework Equations The Attempt at a Solution i think that for a maximum R, theta is 45degres to work out...