Velocity as a Vector Quantity
Because the person always returns to the original position, the motion would never result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity.
when the ball hits the floor and bounces back the momentum of the ball changes.
the rate of change of momentum is the force exerted by the floor on it.
the equation for the force exerted is
f = rate of change of momentum

v is the final velocity which is - 3.85 m/s
u is initial velocity - 4.23 m/s
m = 0.622 kg
time is the impact time of the ball in contact with the floor - 0.0266 s
substituting the values

since the ball is going down, we take that as negative and ball going upwards as positive.
f = 189 N
the force exerted from the floor is 189 N
Answer: C. Some of uranium's mass is converted into energy, so the smaller atoms have less mass.
Explanation:
From Einstein's mass-energy relation:
E = mc²
Mass and energy are equivalent. Mass can be converted into energy and energy into mass.
When Uranium atoms under go nuclear fission, smaller atoms are formed and huge amount of energy is released. This energy comes from the mass difference of the uranium nuclei and new nuclei formed. This mass converted into energy according to Einstein's equation.
A force of charge that drive around a circuit is call electeons