Answer:
Sam's bike hits a curb and he flies over the handlebars, onto the grass.
Step-by-step explanation:
As we know that: Newtons first law of motion states that a body continues to remain in the inertia of rest or motion, unless it is forced to change by applying an unbalanced force. Sam's bike is in uniform motion when suddenly the curb(external force) hits it and makes Sam to fall.