Question

When you flick a coin so that it slides across a table, what four forces are acting on the coin?

Answer 1

Any time the coin is on the table:
-- gravity acting downwards
-- normal force of the table, acting upwards

Any time the coin is moving:
-- friction force, on the coin's underside
-- air resistance
Both of these act opposite to the direction of the coin's motion.

During the flick, while your finger is still touching the coin:
-- the flicking force, a push exerted by your finger
   The force ends as soon as the coin leaves contact with your finger.

Answer 2

Pushing force
friction
gravity
normal force