Quantitative Skills > Teaching Resources > Activities > BotEC: Spacecraft Acceleration

Back-of-the-Envelope Calculations: Spacecraft Acceleration

Barbara Tewksbury

Hamilton College
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Suppose someone offered you a ride to the nearest star in a new spacecraft that could travel at half the speed of light, or about 150,000 km/second. In order to reach such a cruising speed, you and the spacecraft must accelerate from a standstill to half the speed of light. Acceleration means uncomfortable (and maybe even fatal!) "g" forces, that pressed-into-the-seat feeling you get when a car or airplane accelerates. More than 3 g's of acceleration are tough to take for very long, so your spacecraft's engines are designed to accelerate you at not more than 29 meters/second/second (3 times the acceleration due to gravity at the Earth's surface). How long will it take you and your spacecraft to accelerate to half light speed?

References and Resources

This SERC page describes the use of Back of the Envelope Calculations

A View from the Back of the Envelope (more info) : This site has a good number of easy simulations and visualizations of back of the envelope calculations.

The Back of the Envelope : This page outlines one of the essays in the book "Programming Pearls" (ISBN 0-201-65788-0). The book is written for computer science faculty and students, but this portion speaks very well to back of the envelope calculations in general.

Controlled Vocabulary Terms

Subject: Geoscience:Lunar and Planetary Science, Mathematics
Resource Type: Activities:Classroom Activity:Short Activity
Special Interest: Quantitative
Grade Level: High School (9-12), College Lower (13-14)
Quantitative Skills: Estimation
Ready for Use: Ready to Use
Theme: Teach the Earth:Course Topics:Planetary Science
Topics: Solar system, Chemistry/Physics/Mathematics

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