Are these in Inertial Reference Frames?

a) car driving at steady speed on a straight and level road


b) a car driving at steady speed up a 10 degree incline


c) a car speeding up after leaving a stop sign


d) a car driving at steady speed around a curve


e) a hot air balloon rising straight up at a steady speed


f) a sky diver just after leaping out of a plane


g) the space shuttle orbiting the earth





Thanks!

Are these in Inertial Reference Frames?
Hum... the Inertial Reference Frame implies the absence of a net force. Consequently, a body at rest will remain at rest and a body in motion will continue to move uniformly (that is, in a straight line and at constant speed).





Consequently, I'd say a, b and e are examples of IRFs.





c and f are not IRFs because the object is accelerating. d and g are not IRFs because the object is moving in a curve (which, in turn, implies a form of acceleration as well).