A) v = 2*pi*R/T
R = Radius of Earth, 6400 km.
T: T is the period of rotation, i.e. one day. One day = 24 hours. I don't think it's necessary to convert from hours to seconds, since km/h seems like a good unit to stick with.
v = 1675.52 km/h
Now you have v.
F = ma.
a = centripetal acceleration = v^2/r
a = 438.649 km/h^2
F = 42549 km*kg/h^2 (or 3.28 N (kg*m/s^2), if you prefer)
C) Weight = mg. Since gravity is 9.81 meter/second^2, convert this to km/h^2. (g = 127138 km/h^2)
W = 1.233 * 10^7 km*kg/h^2 (or 951.57 N)
D) W - F = a positive number. Therefore, I am at my computer, and not hurtling towards the atmosphere, about to be burnt up.
Oh, and Back_Lit, though Magewout's solution is correct, when finding C, make sure you find the specific heat (J/g*Celsius), and not the heat capacity (J/Celsius).