What is the correct definition of a 'field vector'? a) A measurement that must have both a number and a unit
b) A measurement that can only be measured using scientific digits
c)A measurement that has both a magnitude and direction represented with an arrow
d)A measurement that is drawn in as it cannot be seen visually

i think it is c but can someone help me with this?

A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)

What part of the ear is names after tools, such as the hammer and the anvil?