A reference frame can be moving. To make sure that newtons laws still apply, the reference frame must not be accelerating.
Gravity makes an upward-moving object move 9.8 m/s slower every second.
(30 m/s) / (9.8 m/s²) = 3.06 seconds (rounded)
The velocity is changing.
Ohm's Law is one of the most fundamental and important laws governing electrical and electronic circuits.
