- He feels an upward force to compensate for the downward trajectory of the snowball.
- He feels a backward force exerted by the snowball he is throwing.
- He feels no net force.
- He feels a forward force, the same force that propels the snowball.
This is College physics Answers with Shaun Dychko. A boy is standing on a frictionless ice rink and is initially not moving and he throws a snowball in the positive x direction to the right. That means the boy is exerting a force on the snowball to the right, and so the snowball will in turn exert an equal but opposite the directed force on the boy. So the boy will experience a force backwards.