not posted

For example:

25. A bullet is fired in the air vertically from ground level with an initial velocity 200 m/s. Find the bullet's maximum velocity and maximum height.

26. Find the velocity of an object dropped from a height of 300 m at the moment it hits the ground.

27. A ball tossed in the air vertically from ground level returns to earth 4 s later. Find the initial velocity and maximum height of the ball.

Info:Mathematical Insight Speeds of Rotation and Orbit shows how to find Earth's equatorial rotation speed. To find the rotation speed at any other latitude, you need the following fact: The radial distance from Earth's axis at any latitude is equal to the equatorial radius times the cosine of the latitude.

Question:Use this fact to find the rotation speed for a person at latitude 27. (Hint: When using the cosine (cos) function, be sure your calculator is set to recognize angles in degree mode, not in radian or gradient mode.)

ANSWER should be in KM/HR.

So I know to find where a function is concave down you need to find the second derivative.

This is what I have done so far:

f(x)=e^(-x^2)... f'(x)= [e^(-x^2)]( -2x) therefore f'(x)= (-2x)e^(-x^2).

Then, using the product rule, I found the third derivative:

Product Rule: the derivative of the product of two functions = u'v + uv'

I found that:

u = -2x u' = -2 v = e^(-x^2) v' = (-2x)e^(-x^2)

...therefore...

f''(x) = (-2)[e^(-x^2)] + (-2x)[(-2x)e^(-x^2)]

this simplifies to: (-2)e^(-x^2) + 4(x^2)[e^(-x^2)] ...which simplifies to [-2e^(-x^2)](1-2x^2).

After this is where I get lost. To figure out where the function is concave up or down we have used the table function on our graphing calculator (Press blue "2nd" button then grey "graph" button for TI84Plus). Then we plugged values in but it doesn't seem to help me find the answer. Also we have done something on the graph where we trace the function but I can't remember how to do it. Please help.

*The Book answer to this problem is -1/[(2)^(1/2)] < x < 1/[(2)^(1/2)]. (Read as: negative one over the square root of two is less than x which is less than one over the square root of two.)

This probelm is from "Calculus: Single Variable". 4th Ed. Publishers: Hughes-Harlett, Gleason, McCallum, et al.

What companies/businesses/brands are the best to ask for sponsorship of high school sports? With a small California public high school, there is little budget and opportunities. Which companies are best to approach? Should I look to companies like Adidas, Nike, Under Armour, Champion, Reebok, Footlocker, and Sports Authority(in other words, businesses who are already involved in athletics and exercise who we could get uniforms and equipment from)? or Should I look to companies like Coca Cola and McDonalds who are already known for their contributions to communities?

Why does everyone write "I used to paul up my tricks...". Every site I've seen writes that but I'm pretty sure it should be "I used up all my tricks...". What do you think? Am I correct with "up all" or is there some reason people keep writing "to paul"?

A real image is when you see something inverted (upside down). A virtual image is when you see something erect (right side up). When looking through a pinhole, the pinhole acts as a lens and makes the image smaller or magnified; however, the image is always clear.The image you are supposed to see through a pinhole is supposed to be real (upside down). However, when looking through the pinhole I see a virtual image (everything is right side up). But if you take a candle into a dark room and project it through the pinhole, it projects a real image (upside down). So why don't I see a real image in day light when looking through a pinhole. [Remember: because your eye adjusts its focal length constantly, a pinhole lens does not have a focal length and, therefore, does not change fro virtual to real image relative to the focal point.]

What rule should I use? (If you know a rule please explain) I was wondering if the rule might be that the two shortest lengths have to add up to more than the longest to be a triangle. But then you would have to assume that either YZ (which = 20) is the longest side or that maybe XZ is the longest even though you do not know how long XZ is. Thanks for the help.

Does listening to music make time seem to go by faster when walking?

This isn't any important question. It's just the question I'm going to use for a project and I just wanted to see what people thought. Thank you for your opinion. :-)

Can music make it easier for people whether it is by memorizing things as a song or listening to music as someone is trying to memorize pictures/words?

Pleae and thank you.

This is for my World History final so please help and please answer with accurate information. I f you are not dsure and still want to post an answer, say you aren't sure.