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bobie
bobie
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Conservation of momentum: when rain pours into a wagon

Suppose you have a wagon is moving at constant velocity on a frictionlessfriction-less surface, and rain begins fillingto fill the wagon. 

The net force on the wagon is zero, so momentum is conserved, soconserved; as the mass of the wagon increases, the speed decreases. On the other hand,But if the velocity of the wagon changes, the net force can't be zero, right? 

There has to be some force opposing the motion of the cartwagon to slow it down. How do we reconcile this?

Conservation of momentum: rain into a wagon

Suppose you have a wagon moving at constant velocity on a frictionless surface, and rain begins filling the wagon. The net force on the wagon is zero, so momentum is conserved, so as the mass of the wagon increases, the speed decreases. On the other hand, if the velocity of the wagon changes, the net force can't be zero, right? There has to be some force opposing the motion of the cart to slow it down. How do we reconcile this?

Conservation of momentum when rain pours into a wagon

Suppose a wagon is moving at constant velocity on a friction-less surface, and rain begins to fill the wagon. 

The net force on the wagon is zero, so momentum is conserved; as the mass of the wagon increases, the speed decreases. But if the velocity of the wagon changes, the net force can't be zero, right? 

There has to be some force opposing the motion of the wagon to slow it down. How do we reconcile this?

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Kyle Kanos
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math_lover
math_lover
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Conservation of momentum: rain into a wagon

Suppose you have a wagon moving at constant velocity on a frictionless surface, and rain begins filling the wagon. The net force on the wagon is zero, so momentum is conserved, so as the mass of the wagon increases, the speed decreases. On the other hand, if the velocity of the wagon changes, the net force can't be zero, right? There has to be some force opposing the motion of the cart to slow it down. How do we reconcile this?