A car is driving northwest at v mph across a sloping plain whose height, in feet above sea level, at a point N miles north and E miles east of a city is given by

h(N,E)=4750+75N+25E.

AAt what rate is the height above sea level changing with respect to distance in the direction the car is driving?

rate =

BExpress the rate of change of the height of the car with respect to time in terms of v.

rate =