A ball is released from rest and falls through air until it eventually attains a constant velocity. During this motion, forces X and Y change with time as shown. What could forces X and Y be?
- Aforce X: air resistance; force Y: resultant force
- Bforce X: air resistance; force Y: weight
- Cforce X: upthrust; force Y: resultant force
- Dforce X: upthrust; force Y: weight