Answer in units of m/s. 007 (part 2 of 3) 10.0 points

With what velocity does it leave the ground?

Answer in units of m/s.

008 (part 3 of 3) 10.0 points

If the tennis ball were in contact with the

ground for 0.0102 s, find the acceleration

given to the tennis ball by the ground.

Answer in unity of m/s?.

009 10.0 points

A reconnaissance plane flies 688 km away from

its base at 366 m/s, then flies back to its base

at 549 m/s.

What is its average speed?

Answer in units of m/s.

Independent variable is something that is changed in a experiment. 

Answer body lying face up ;

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current