Kinetic energy of an emitted alpha particle from a stationary thorium nucleus (a = 220, z = 90) is e0. What should be the kinetic energy of the recoiling nucleus?.

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?

i think if it were me i whould divide 300 dide 15

step-by-step explanation:

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.