I've got an energy and work problem. the premise of the problem is: a crate with a mass of m is on a ramp that is inclined at an angle of 30° from the horizontal. a force with a magnitude of f directed parallel to the ramp is used to pull the crate with a constant speed up the ramp a distance of d. there are a set of subquestions and i've answered them as best as i can, but i don't think i'm right. could someone give me the answers and me understand why i'm wrong? 1. what is the work done on the crate by the applied force f? --i said cos30 * f * displacement 2. 2. what is the work done on the crate by the gravitational force exerted on the crate by earth? --i said m*9.8*tan30 3. what is the work done on the crate by the normal force, with a magnitude of fn, exerted on the crate by the ramp? (hint: recall that the normal force is perpendicular to the surface of the ramp.) --i said zero 4. what is the work done on the crate by the frictional force fk? --i don't understand this one 5. what is the total force acting on the crate? --i said f, as in the pre-defined force 'f' 6. what is the work done on the crate by the total force? --i don't understand how this is different from the first one

An isolated conducting spherical shell carries a positive charge. part a which statement (or statements) about the electric field and the electric potential inside and outside the spherical shell is correct? which statement (or statements) about the electric field and the electric potential inside and outside the spherical shell is correct? electric potential inside the shell is constant and outside the shell is changing as 1/r2 both the electric potential and the electric field does change with r inside and outside the spherical shell electric potential inside and outside the shell is constant, but not zero electric potential inside the shell is constant and outside the shell is equal to zero electric field inside and outside the shell is constant (does not change with the position r), but is not equal to zero electric field inside and outside the shell is changing as 1/r (where r is the distance from the center of the sphere) electric field inside is equal to zero and outside the shell is constant, but not zero electric potential inside the shell is constant and outside the shell is changing as 1/r electric field inside and outside the shell is changing as 1/r2 electric field inside is equal to zero and outside the shell is changing as 1/r2 electric field inside and outside the shell is zero electric field inside is constant and outside the shell is changing as 1/r

An electron is traveling with initial kinetic energy k in a uniform electric field. the electron comes to rest momentarily after traveling a distance d. (a) what is the magnitude of the electric field

Emagnitude of the electrical force acting between a +2.4 ×  10–8  c charge and a +1.8 ×  10–6  c charge that are separated by 0.008 m is    n, rounded to the tenths place.