When a force is exerted on an object, work is done only if the object

Find the volume of the ellipsoid x^2+y^2+5z^2=36.

Let f(x) = x4- 8x2 . find the relativeextrema of this function using the second derivative test.

Assume this car is driven off a cliff . how many arrows of force need to be drawn in the free body diagram? assume no air resistance -five -one -three -four