Which of these would be an example of unbalanced forces? a. you stand very still during the national anthem. b. your coffee cup does not move from its original spot on the desk. c. a dog runs at a constant velocity. d. a snowball picks up speed as it rolls down the mountain.

The anwser is: wave a has a greater pitch and frequency.

I'm having some difficulty seeing the diagram clearly.but the question says there's a net inward force on the object.so we know right away,  from newton's 2nd law of motion, thatthat baby is accelerating.  it doesn't even matter which way thenet force is pointing.  if there's any net force, then either theobject's speed or else its direction must be changing.