Just one short question, I've ended up with a equation for the time t (question c), could you disconfirm or confirm it? My answer is:
t=1/2*d*A1/A2*sqrt(2)/sqrt(g*(h-d))
I've tried that as well! But then I run into the problem of determining the speed of the water before it enters the straw (in other words: the speed of the flow in the glass)...
Okey, so using the that, I get that the speed at the end of the pipe is:
v = sqrt(2dg-2gh+(v0)^2)
But I've gotten this far before, my problem is to determine the speed v0 when the water is entering the straw... My guess is that it can be determined by some relationship between y1, A1 and...
Hey,
One of my homework tasks is, embarrasing, too hard for me to tackle without some help. So I help somebody can help me with the following problem:
TASK:
"You have a filled glass of water. A straw is stuck partly down into the glass (a depth d from the surface), the other end of the...
Hey,
I've been looking on this problem:
"You have two cars with equal mass and speed (50km/h), which crash head on. One driver is wearing a seat belt (situation 1), the other not (situation 2). Calculate the force and impulse on each of the drivers during the collision. You can assume that...
This is indeed a difficult question to answer!
I think I will answer the task by saying:
" Friction can't do positive work, because:
(1) In the case of kinetic friction: Kinetic friction always oppose motion so
W = F*d*cos(x>90 degrees) = - F*d
(2) In the case of static friction...
Just one last thing:
To mezarashi: Could you give me those examples?
Because as far as I understand it now, kinetic friction will always do negativ work (relative to the direction of motion), while static friction can do positive work, but is a passive force so it really doesn't count...?