A ball is thrown horizontally with an initial velocity of 20 m/s from the top of a tower
60 m high. What is the initial vertical
velocity of the ball?
a. O m/s
b. 20 m/s
c. 3.5 m/s
d. 9.81 m/s

Ahuge (essentially infinite) horizontal nonconducting sheet 10.0 cm thick has charge uniformly spread over both faces. the upper face carries +95.0 nc/m2 while the lower face carries -25.0 nc/ m2. what is the magnitude of the electric field at a point within the sheet 2.00 cm below the upper face? (ε0 = 8.85 × 10-12 c2/n · m2)