If a proton were released from rest at the sphere's surface, what would be its speed far from the sphere?

Let the sphere is having charge Q and radius R

Now if the proton is released from rest

By energy conservation we can say

now take square root of both sides

so the proton will move by above speed and

here Q = charge on the sphere

R = radius of sphere

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?

momentum of soft ball three times less than baskey ball