How could you use a yo-yo to model how Earth's gravity acts on
the moon to keep it in orbit around
Earth?

In all trials, the magnitude of the final velocity for g1 + g2 was less than the magnitude of any initial velocity. as mass increased, what happened to the velocity? the velocity decreased. the velocity increased. the velocity of g1 + g2 could not be measured. the velocity was not affected by the mass increase.

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?

Could we see a galaxy that is 20 billion light-years away?