If c is the curve given by r(t)=(1+2sint)i+(1+3sin2t)j+(1+1sin 3t)k, 0≤t≤π2 and f is the radial vector field f(x, y,z)=xi+yj+zk, compute the work done by f on a particle moving along c.

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

Imagine an isolated positive point charge q (many times larger than the charge on a single proton). there is a charged particle a (whose charge is much smaller than charge q) at a distance from the point charge q. on which of the following quantities does the magnitude of the electric field created by charge q at particle a's position depend? check all that apply.the type of the charge on the charged particle athe relative orientation between q and a (while the distance between q and a is fixed)the specific location of the charged particle a (while the distance between q and a is fixed)the amount of the charge on the point charge qthe specific location of the point charge q (while the distance between q and a is fixed)the distance between the point charge q and the charged particle athe amount of the charge on the charged particle a

Can any one me on number 4? i do know that it’s not a cause i gotten that wrong on the first try.