(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Andy (mass 92 kg) and Sam (mass 75 kg) are both on toboggans (each toboggan has a mass of 4.6 kg) travelling on a crash course towards each other. Just as they hit, they lock hands so they move together as one. What is their new speed? In what direction do they travel?

m_{A}= 96.6 kg

v_{A}= 8.8 m/s at 8.7 degrees above horizontal (headed +x direction)

m_{S}= 79.6 kg

v_{S}= 6.7 m/s at 7.3 degrees below horizontal (headed +x direction)

m_{A}+ m_{S}= 176.2 kg

v_{f}= ?

2. Relevant equations

m_{A}v_{A}+ m_{S}v_{S}= m_{A}v_{A}' + m_{S}v_{S}'

3. The attempt at a solution

Tried finding x and y components and unsure what to do next.. since Andy is headed southeast, do I make that y-component negative? Am I combining too much into these equations? I am so confused with these questions where 2 things are moving at the same time or at non-right angles to each other. Can someone break these problem types down for me so that I have a step by step approach to them? I end up with equations and have no idea how to follow through. Here, I have 2 equations and 2 unknowns in each equation. I don't know what to do next or if this is even correct.

(96.6)(8.8 cos 8.7) + (79.6)(6.7 cos 7.3) = (176.2)(v_{f}cosσ)

7.77 = (v_{f}cosσ)

(96.6)(8.8 sin 8.7) + (79.6)(6.7 sin 7.3) = (176.2)(v_{f}sinσ)

1.11 = (v_{f}sinσ)

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# Homework Help: 2D completely inelastic collision question

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