







Throwing a ball on the moon 
20080521 

From leria: equation for motion of moon is h=2.67t^2 + vt + s
equation for earth h=16t + vt + s
Suppose you are on an outpost on the moon and Jan is back on Earth. Both people toss a ball from a height of 96 feet with an initial velocity of 16 feet per second. How much longer will your ball stay in motion on the moon than Jan's on the earth?
Math Central,
I'm having a difficult time understanding which numbers to plug into the formula. Answered by Stephen La Rocque. 





Separate three different sized marbles 
20080307 

From Jana: hello, I love this site, it explains everything so well. I have been asked a question in science, it asks for me to make a devise which separated three different sized marbles. I have thought this through alot but it still never makes sense to me. Everything i seem to think of never works out or has something that will make it not work. I'm really stuck on this one...please help me..! Thankyou so much Jana Answered by Stephen La Rocque. 





The distance to the moon from earth 
20060519 

From Maira: Using trigonometric functions first, show how to find the distance to the moon from earth and then find the radius of the moon. Answered by Stephen La Rocque. 

