Now let's focus on the descending sphere. let m be the mass of the sphere, g be the acceleration due to gravity, t be the magnitude of the force of tension of the string, a be the acceleration of the sphere as it descends, and α be the angular acceleration of the wheel. what is the correct expression for newton's second law applied to the descending sphere? a. mg+t = ma
b. mg+t = mα
c. mg-t = ma
d. mg-t = mα
e. -mg+t = ma
f. mg-tr = ma
g. mg+tr = ma