Does the green LED emit light when you connect the banana plug wires across it? What does that say about the threshold voltage of the green LED compared to the blue LED?

Yes.

Explanation:

-This is because the threshold voltage for the green light is much lower than that of the blue light.

-A longer wavelength in the greenlight necesitates the need for a lower voltage in the banana plug.

the first, second, and fifth options

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.