Image

Fun with Fundamentals: Problem 228

Aug. 1, 2000
Jebediah Dean was settin' in his frictionless wheelchair one sunny afternoon when he decided he needed to git back to the "facilities"

Problem 228 - Spittin' mad

Jebediah Dean was settin' in his frictionless wheelchair one sunny afternoon when he decided he needed to git back to the "facilities." Now, ol'Jeb didn't want to set down his 'shine for fear that Blue the Coon-hound would drink it down. As Jeb ponders his predicament, he spits some chaw into a spittoon, causing his chair to move backwards.

Next thing ya know, ol' Jeb's on his way. How many times must he spit to accelerate to 1 m/sec? (Assume ol' Jeb sips on his brew every so often to wet his whistle).

Whatcha need to know:

Jeb (and his frictionless wheelchair) weigh 50 kg

"Projectile" speed = 5 m/sec

Assume the chaw is consistent with water

Solution to July's problem, 227:

You'll be left in the dark if you didn't know the professor's plan won't work, here's why:

As explained by reader, Jun Asai of Chesapeake, Va.,

Since the mass involved = 2 mg of antimatter and 2 mg of matter per day, Einstein's theory of relativity states:

e = mc2

(0.00004kg) × (3 × 108m/sec)2 = 3.6 × 1012 Nm

And we know that there are 86,400 seconds in each day so,

Power = energy divided by time, or:

Considering the efficiency of the professor's machine:

41.67 MW × 0.03 = 12.5 MW

Which is still inadequate, leaving Edisonville in the dark.

Here are the results

The winner is... Fun Problem 226:

Catch of the day, June, 1999:
Total entries: 155
Number correct: 65 (41.9%)
Winner: Lee Ruiz, Indianapolis
Lee's prize: Maple V software
Technical consultant: Jack Couillard, Menasha, Wis.

Related Article

Fun with Fundamentals: Problem 227

Sponsored Recommendations

June 6, 2025
In the rapidly evolving landscape of industrial manufacturing, reliability, productivity, and worker safety take precedence. However, traditional connectivity approaches often...
June 6, 2025
Amidst the rapid evolution of electronics manufacturing, reliability, productivity, and worker safety remain paramount concerns. Yet, traditional connectivity methods often falter...
June 6, 2025
While many within the industrial manufacturing sector grasp the importance of smart manufacturing for optimizing processes, boosting productivity, and future-proofing operations...
June 6, 2025
For electronics manufacturers grappling with formidable challenges, navigating the path to success requires adapting to the dynamic landscape of the industry. How can electronics...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!