Question

net force worksheet
possible points 2.66
in the picture shown above with the penguin sliding across the ice to the left, why was there no arrow for applied force to the left on the diagram?
it should be drawn facing down
just because something is moving to the left, it does not mean there is a force acting to the left
because there is no gravity on ice
this was a special case because the skater was a penguin

Explanation:

According to Newton's first law of motion, an object in motion will stay in motion with a constant velocity (in a straight line) unless acted upon by an external force. So, the penguin's motion to the left doesn't imply a continuous applied force to the left. Gravity (\(F_g\)) acts downward and the normal force (\(F_N\)) acts upward. There's no indication of an applied force in the horizontal - left direction just from the motion itself.

Answer:

B. just because something is moving to the left, it does not mean there is a force acting to the left