For the same reason that you can skate around a curve at constant speed but not with constant velocity.
The DIRECTION you're going is part of your velocity, but it's not part of your speed.
If the DIRECTION changes, that's a change of velocity.
The object doesn't have to change speed to have a different velocity. A change of direction is enough to do it.
And any change of velocity is called acceleration.
Answer:
(B) Boundary work
(D) Heat
Explanation:
Boundary work and heat quantitatively describe the transition between equilibrium states of thermodynamic systems. They are not only a function of the initial and final states, but also of the successive intermediate states through which the system passes, this is, depend on the path taken to reach one state from another. Thus, are path functions.
Answer:
"Planets May Affect the Chemistry of Their Stars. Planets are, by and large, at the mercy of their stars. Not only do stars provide a ready energy source of radiated light and heat, but the mass and gravitational pull of stars flat-out dwarfs the summed masses and pulls of any orbiting companions."