Question

Conservation of momentum

Answer 1

The combined velocity of Sally and the sled is 1.688 meters per second.

Step-by-step explanation:

Let suppose that Sally collides inelasticly, meaning that final velocity of Sally-sled system can be determined solely by Principle of Momentum Conservation:

`m_(S)\cdot v_(S, o) + m_(s)\cdot v_(s,o) = (m_(S)+m_(s))\cdot v` (1)

Where:

`m_(S)` - Mass of Sally, measured in kilograms.

`m_(s)` - Mass of the sled, measured in kilograms.

`v_(S,o)` - Initial velocity of Sally, measured in meters per second.

`v_(s,o)` - Initial velocity of the sled, measured in meters per second.

`v` - Final velocity of the Sally-sled system, measured in meters per second.

If we know that
`m_(S) = 54\,kg`,
`m_(s) = 10\,kg`,
`v_(S,o) = 2\,(m)/(s)` and
`v_(s,o) = 0\,(m)/(s)`, then the final velocity of the system is:

`v = (m_(S)\cdot v_(S,o)+m_(s)\cdot v_(s,o))/(m_(S)+m_(s))`

`v = 1.688\,(m)/(s)`

The combined velocity of Sally and the sled is 1.688 meters per second.