Table of Contents
Kick Off Questions
- What does the net force acting on an object mean? That is, what is a good working definition for net force?
- What is the relationship between the net force acting on an object and its acceleration?
- Under what conditions is it appropriate to use the kinematic equations to describe the motion of an object?
Project 2: Learning goals
- Predict the motion of a single-particle system executing constant velocity or constant acceleration motion using appropriate representations (this includes verbal, graphical, diagrammatic, mathematical, and computational representations).
- Collect, analyze, and evaluate data to determine the type of motion and the properties of the motion of a single-particle system.
- Evaluate the applicability/limitations of models and the validity of predictions for different types of motion.
- Apply the momentum principle ($\Delta\vec{p}=\vec{F}\,\Delta t$; $d\vec{p}=\vec{F}\,dt$) iteratively/computationally to predict the motion or determine the properties of motion/net force acting on a single-particle system where the net force is not constant (e.g., due to spring-like restoring forces or dissipative drag forces).
Project 2: Learning Concepts
- Forces cause changes in momentum
- Kinematic Equations - Constant Acceleration
- Gravitational Force Near Earth
- Vector Components
- $\vec{F}_{net} = m\:\vec{a} = \dfrac{\Delta\vec{p}}{\Delta t}$
- Iterative Prediction of Motion
Project 2: Part A: Escape from ice station McMurdo
You are a member of a scientific research team at McMurdo ice station which is funded by the Carver Media Group in Antarctica.
Two members of your research team have just returned from investigating an incident at another facility nearby, which is a launch site for a communications satellite. When they returned they brought with them a burnt humanoid body with two faces, and reported the facility otherwise empty. They also reported that no satellites had been launched from that facility, so they launched the satellite. However, in their haste to leave they launched the wrong satellite! Luckily for you, dealing with that satellite (and what it contained) is a problem for another day.
Since the disturbing discovery several inhabitants of the ice station have disappeared. Frightened, a member of your team decided to flee the station on a fan powered hovercraft. You receive a distress call not long after their escape that their steering and acceleration controls have been jammed and they need your help.
| Time | Your Team Member's Position | Your Position |
|---|---|---|
| 0 s | 2536.40 m | 10.47 m |
| 10 s | 3072.80 m | 41.88 m |
| 20 s | 3609.20 m | 94.22 m |
You decide to attempt a rescue in another hovercraft. You must decide how many members of your team help in the rescue operation. The hovercrafts do not have a velocity or acceleration gauge but they do have GPS locators and you possess your trusty stopwatch. The GPS locator tells you the exact position of both your craft and other team members' craft relative to the ice station. You are following their path. You collect the following data for the first 20 seconds of your journey.
You need to tell the runaway researcher the exact time from your starting time to jump onto your hovercraft as you may only have one shot at this rescue.
Project 2: Part B: Escape from ice station McMurdo
Just as you are about to radio the time to jump to the runaway researcher, you realize the steering and acceleration controls have become frozen on your hovercraft and so it continues to accelerate and you cannot change direction. 200m ahead of the point at which you were going to tell the researcher to jump is an ice ravine. At the bottom of the ice ravine, 400m below, is an unfrozen salt water pool surrounded by stalagmites. From the ravine's edge to the pool is 490m and the pool stretches for 900m. You are moving too quickly to survive jumping off the hovercraft, but might survive the fall into the pool by staying on the hovercraft; it has seat belts. You now have a choice to make, to stay on your hovercraft or jump to the runaway researcher's hovercraft. One or both may make it to the pool. Your choice may be the difference between life and death.
