Question

A 90 kg sled with 2 kids in the sled ride down a hill with a speed of 4m/s.The sled hits the kids father,mass of 130kg and he falls onto the sled.what is the velocity of the sled after acceleration.

Answer 1

Answer:1.636$ms^{-1}$

Explanation:

Let $m_{1}$ be the mass of sled and children before impact.

Let $m_{2}$ be the mass of sled,children and their father.

Let $v_{1}$ be the velocity before impact.

Let $v_{2}$ be the velocity after impact.

The momentum can be conserved because there are no external forces that can affect the momentum.

This is a inelastic collision.

Given,

$m_{1}=90Kg\\m_{2}=90+130=220Kg\\v_{1}=4ms^{-1}$

So,

$m_{1}v_{1}=m_{2}v_{2}$  

$90\times 4=220\times v_{2}\\v_{2}=1.636ms^{-1}$