kavlas

Thank you. Now i have the following question: Suppose the distance between the cannon and the wall is c kilometres ( c is the speed of light) and the ball is fired against the wall with c speed ,while the cannon is rushing against the wall with c/2 speed.After what time the ball will meet the cannon??Is the above formula applicable in this case too??

Suppose a cannon fires horizontaly a perfectly elastic ball against a perfectly elastic wall, distant x, with speed v and at the same time starts rushing against the wall with speed u. Will the time taken for the ball to hit the wall and come back to the cannon be given by the following formula: [math] t=\frac{2x}{v+u}[/math]??

I am sorry i cannot see why you are doing that.

Thank you ,thank you for the reference i should have known better

Why?

It has been said that for a star to turn into a black hole must have 4 or 5 the size of our sun. Is that due to observations or calculations?? Sorry if my question sound naive to the experts in the field. Thanks

Hi everyone There two problems that bother me for quite some time. 1)If [math]\lim_{x\to\infty}\frac{f(x+1)}{f(x)}=2[/math] then find [math]\lim_{x\to\infty}\frac{f(x+2)}{f(x-2)}[/math]. 2) I do not know if this the right place to ask for this problem but here it goes. Can we prove the De Morgan law? Thank you