Recent content by Kristin_Z

I've been looking at relative motion equations in 2d and having no problem but when I saw this one my brain was certain that somehow it had to be super complicated. Its not though. Thanks, is all makes sense now.

Homework Statement A cheetah can run at approximately 100km/hr and a gazelle at 80km/hr. If both animals are running at full speed, with the gazelle 70m ahead, how long before the cheetah catches its prey? Homework Equations s=vt (no acceleration) v = km/hr / 3.6 = m/s The Attempt at a Solution...

I think I have it now. 2y = 1/2 at12 divided by y = 1/2 at22 gives me 2= t12t22 so t1t2 =square root of 1/2. Thanks for your help, still not entirely sure I understand what I did. I guess that's what practice is for.

A ball moving with speed v rolls off a shelf of height h and strikes the floor below a distance x1 from the edge. A second ball moving with the same speed rolls of a self of height 2h and strikes the floor a distance x2 away from the edge. Determine the ratio of distances x1/x2. \Deltax=Vxt...

Thank you I tried the equation above and got an answer of Vi=0.23m/s I am doing this course via distant education, so there is not much support. The print out they supplied did not even include the equation I needed to figure out this problem so I was searching online. I really appreciate...

My, what a humbling comment. Right then, I'll go back to the equation I had originally used and I'll try to work it out. 3.0m=v_i + 1.2m/s/2 * 4.2s 3.0m/ 4.2s= 0.714 0.714-1.2=v_i/2 -0.486 x 2 = v_i v_i = 0.97m/s Should I just give up now?

Thanks for your help malawi_glenn, I feel like the silly girl sitting in the room full of math geniuses all over again.

So the equation is wrong? That's silly, I took it off of the website I was provided with through school. Go figure. So the answer is initial velocity is -0.843m/s. Is this right?

1. Can someone please help with this equation 2.An accelerating lab cart passes through two photo gate timers 3.0 m apart in 4.2 s. The velocity of the cart at the second timer is 1.2m. What is the cat's velocity at the first gate? 3. So I am so confused as to how to find the initial velocity. I...