Thomas Edison is the answer im 100% sure of it.
I want to say that they will be primarily flat but I honestly don't know
Answer:
Centripetal acceleration.
Explanation:
Centripetal acceleration is a property of a body moving in a uniform circular path and it is directed radially towards the center of the circle in which body is rotating.
The force which causes this acceleration is centripetal force which is also directed towards the center of the circle and pulls the body towards its center.
It is calculated through following formula

where v is velocity and r is the radius of the circle.
The boy’s foot causes the motion. His foot is the one that causes the ball to roll down the hill.