Recent content by Kandy

and even if you divide by 2 for whatever reason, you still wouldn't get 4.5s, so... well, thanks!

well, i could be wrong about total time, the question maybe asking for smthg else... I geuss I'll check if the ans key is wrong tomorrow... :wink:

Here's the question: An object fired straight upward with an initial velocity of 1.0 x 10^2 m/s is subjected to the effects of gravitation. In a previous question, I solved for max height, which was 5.1 x 10^2 m. (I'm not sure if this is related to the next question though). The time the...

In a question, it asks for the time that an object is in the air; at first I thought it meant the time at max height, but I was told it should be the time at max height divided by 2 because the object goes up and down. But if the object goes up and down, wouldn't you mult by 2?

I got the same answer (0.6 and 4) now, but I used a graphing calculator; I don't know how to get to t={-b+/- sqrt... because I haven't learned how yet.

A roof tile falls from rest from the top of building. An observer inside the building notices that it takes 0.20 s for the tile to pass her window, whose height is 1.6 m. How far above the top of this window is the roof? I attempted this question about 2 or 3 different ways but they don't...

12.0[m] + 7.0[m/s] t = 30.0[m/s] t - 0.5 (-9.81[m/s^2]) t^2 0 = -4.91[m/s^2] t^2 + 23.0[m/s] - 12.0[m] factor product=59 sum=23.0 the two numbers are 2.95 and 20.05 (-4.91 t^2 + 2.95t) (20.05 t - 12.0) t (4.91 t + 2.95) (20.05 t - 12.0) t=0 4.91 t + 2.95 = 0 4.91 t = -2.95...

i don't understand why the speed of the balloon needs to be added to the initial speed of the bullet.

I redid the problem but I still can't get it because the two times are the same. What did I do wrong now? vt-12.0=Vt+0.5(-9.81)t^2 7.0t-12.0=30.0t+(-4.91)t^2 7.0t-12.0=30.0t-4.91t^2 0=-4.91t^2+30.0t+12.0 P=-58.9 S=30.0 (-4.91t^2+31.85t)(-1.85t+12.0) t(-4.91t+31.85)(-1.85t+12.0)...

A hot air balloon is ascending straight up at a constant speed of 7.0 m/s. When the balloon is 12.0m above the ground, a gun fires a pellet straight up from the ground level with an initial speed of 30.0 m/s. Along the paths of the balloon and the pellet, there are two places where each of them...

thanks, I thinki got it now

for d), isn't it asking how far above the trampoline was Babette before she fell, and Babette is the one falling, so what does this question have to do with Pepe jumoing on the trampoline?

ok, so I see now, it is +at, not ad, so it makes sense now: b) vf=-98.1m/s and for c), i think this should be correct: vf=at+vi vf=(-9.81m/s^2)(10.0s)+15.0m/s vf=-83.1m/s but for d), I'm having a bit of trouble: the formula d=vit+(1/2)at^2 should be used, i expected that Babette's vi...

the first way you mentioned was way to deep, I havn'tgotten to that yet, but I assumed it was at STP as you said, and I went 0.335g x 22.4L / molar mass andthat gave me the volume to compare with 250mL. I havn't learned about Ideal gas Law yet, so it's kind of difficult for me.but thanks for...

Pepe, the clown, is jumping on a trampoline as Babette, the tightrope walker, above him suddenly loses her balance and falls off the tightrope straight toward Pepe. Pepe has just started upward at 15.0 m/s when Babette begins to fall. Pepe catches her in midair after 10.0s. a) How far has...