Mary and debra stand on a snow-covered roof. they both throw snowballs with the same initial speed, but in different directions. mary throws her snowball downward, at 30° below the horizontal; debra throws her snowball upward, at 30° above the horizontal. which of the following statements are true about just before the snowballs reach the ground below? (there could be more than one correct choice.)

a. mary's snowball has a greater downward acceleration than debra's snowball.
b. debra's snowball has exactly the same acceleration as mary's snowball.
c. debra's snowball will stay in the air longer than mary's snowball.
d. mary's snowball will stay in the air longer than debra's snowball.
e. both snowballs will take the same amount of time to hit the ground.

One kind of e-book display consists of millions of very small spheres that float in a thin fluid layer between two conducting transparent plates. each sphere is black on one side and white on the other, and possesses an electric dipole moment directed from the white side to the black. when an electric field is applied between the plates, the spheres rotate so that their dipole moment lines up with the field. depending on the fields direction, either the black or the white sides of th espheres can be made visible.the dipole moment of the spheres can be modeled as two opposite charges of magnitude 3.5 x 10^-15 c, separated by a distancce of 100 micrometers (um). what is the maximum possible torque on a sphere if the electric field between the transparent plates is 4.0 x 10^5 n/c