---
title: Perfectly Inelastic Collision
topic: Momentum and Impulse
author: John Hopkinson
source: PHYS 112 2014 W Midterm 2 Section 002 Q5
template_version: 1.3
attribution: standard
partialCredit: true
singleVariant: false
showCorrectAnswer: false
outcomes:
- 7.2.1.2
- 7.2.1.3
- 7.5.1.3
- 7.5.1.4
- 7.5.1.9
- 7.6.1.0
- 7.6.1.2
difficulty:
- medium
randomization:
- 2
taxonomy:
- undefined
span:
- section
length:
- average
tags:
- PW
assets:
- 2Dconservation.png
part1:
  type: number-input
  pl-customizations:
    rtol: 0.05
    weight: 1
    allow-blank: true
    label: $v_f= $
    suffix: $v$
part2:
  type: number-input
  pl-customizations:
    rtol: 0.05
    weight: 1
    allow-blank: true
    label: $\theta_f= $
    suffix: $^{\circ}$
myst:
  substitutions:
    params:
      vars:
        title: Perfectly Inelastic Collision
      v1: 1
      v2: 2
---
# {{ params.vars.title }}
Particles of mass $m$ and $2m$ have velocities $v_1=$ {{ params.v1 }}$v\hat{x}$ and $v_2=$ {{ params.v2 }}$v\hat{y}$ respectively.

<img src="2Dconservation.png" alt="Figure of a particle of mass m travelling to the right with velocity v1 along the x-axis and a particle of mass 2m travelling up with velocity v2 along the right axis. The two particles collide and form a resulting particle of mass 3m which moves with velocity v f at an angle theta f with respect to the x-axis." width=400>

## Part 1

After undergoing a perfectly inelastic collision as shown in the figure, what velocity, $v_f$, does the resulting particle have? Enter the magnitude of $v_f$.

### Answer Section

Please enter in a numeric value.

## Part 2

What angle with respect to the $x-$axis, $\theta_f$, does the resulting velocity make?

### Answer Section

Please enter in a numeric value in degrees.

## Attribution

Problem is licensed under the [CC-BY-NC-SA 4.0 license](https://creativecommons.org/licenses/by-nc-sa/4.0/).<br> ![The Creative Commons 4.0 license requiring attribution-BY, non-commercial-NC, and share-alike-SA license.](https://raw.githubusercontent.com/firasm/bits/master/by-nc-sa.png)