Question

A 1000 kg train car traveling at 12 m/s on a level track has 400 kg of sand dumped, vertically, into it. What is the final speed of the train car after the sand is dumped into it? Ignore friction

Answer 1

The final speed of the train car is 8.57 m/s.

Step-by-step explanation:

Given that,

Mass of train car = 1000 kg

Mass of sand = 400 kg

Speed of train car = 12 m/s

We need to calculate the final speed of the train car after the sand is dumped

Using conservation of momentum

`m_(1)u_(1)=(m_(1)+m_(2))v`...(I)

Put the value in the equation (I)

`1000*12=(1000+400)v`

`v=(1000*12)/(1400)`

`v=8.57\ m/s`

Hence, The final speed of the train car is 8.57 m/s.