Physics question from a n00b

[RobinK]

Hey guys. Hope you're having a good summer. Anyways, here's a problem I don't get bc I'm a physics scrub.

A 1500kg car accelerates uniformly from 60.0 kg/hr to 90.0 km/hr in 6.00 s along a level stretch of road. If the combined resistive forces acting on the car to due to both friction and air resistance have an average value of 575 N during the acceleration period, then what is the average power required of the car?

Help a noob pl0x

[darksaber21]

[darksaber21]

[RobinK]

Wow! Thank you! :D

[smeag]

I don't understand the logic behind this problem...

A 2.0 kg brick with dimensions 20 cm x 9 cm x 6 cm is placed upon a flat surface. What is the minimum total number of whole bricks that will need to be stacked on top of one another so that the pressure exerted on the surface
by the bottom most brick is equal to atmospheric pressure, 1.013 x 10^5 Pa?

Thanks for explaining!

[darksaber21]

[smeag]

thanks darksaber21, by the way, how are you faring in the physics portion of the UIL science tests?

[darksaber21]

I'm typically averaging 70 on that section, minus the guided reading questions in the start of the section. I've been more focused on biology lately (because I hate it and don't remember much from it at all), and I've been more focused on the last few questions in the physics sections, the non-kinematic ones. I'm getting a lot better on them, but now the only things I need to work on is to teach myself waves and optics (minus doppler's effect), and fix up on angular momentum and conservation of rotational energy. Currently, I'm teaching myself magnetism (while reviewing electricty).

You might or might not ask, I'm only teaching myself physics (and some biology) because that stuff is outside the cirriculum (I'm taking physics B because they don't offer C at my school :(, but I'm still taking the C test anyway). So, yeah...
Chemistry is fine I suppose, all the questions are ridiculously easy, but I haven't done it in a while and I'm prone to stupid mistakes (hence a 222 for me at invitational B instead of a 246).


How are you faring at this point?

[smeag]

Well, I am basically the opposite of you... I find the biology very easy while the electricity and magnetism portion of the physics test seems mostly easy... I guess where I struggle the most is with torque and optics

by the way, what do you use to study for chemistry?

[darksaber21]

Umm.. whatever textbook they gave me last year... umm "Chemistry: The Central Science" by Brown, (revised 8th edition?) I think. I had that textbook for two years though (pre-ap and AP used the same book), so I basically learned a lot from it. It focused a lot on concepts more than the math though, so it's up to you.

I got myself a textbook by Zumdal for review, and it's okay I guess. Haven't really looked into it very much to say much more. It's structured a lot differently than I'm used to though, haha, but I'll adjust. My chemistry teacher last year recommended me that textbook, and said it focuses more on math than concepts, so it's handy for practice problems. I perfer to understand concepts first, but since I know most of them, this textbook shall do, and any concept I don't know I'll either ask people or research on my own time (probably the latter).