If there was a cake weight 9N what will it's normal force be

Answer 1

We need to know more about the state of the cake. You know its weight is 9 N, which is the downward force due to gravity. If the cake is free falling then there is no normal force acting on it. If the cake is sitting at rest on a flat table top, then the normal force would be countering the weight force, so 9 N but in the opposite direction of the weight force. If your cake is sitting at rest on an inclined plane, then the normal force would be equal and opposite to the y-coordinate of the weight force.