Dots

What is negative acceleration and how does it affect the movement/motion of an object? How can you tell if something is moving with a negative acceleration based on, say, velocity-time graph (e.g. is it determined by the gradient)? I would really appreciate a thorough but easy-to-understand answer. I've been confused by this topic for ages, especially when the whole velocity-time graph comes into the picture.

Does a falling object increase in speed if its acceleration of fall decreases? Why or why not? Please explain as thoroughly but as simply as you can. I'm really confused.

So my parents say I can get an acting agent, but the problem is that the ones in my country aren't as good as those in LA (I live in a very small country). I'm going to LA this December, and my parents say I should email some agents and arrange stuff with them so that I can, perhaps, audition for somethings in December. I just wanted to ask two things:

1. Can acting agents have clients overseas?

2. What are some good companies that supply good acting agents?

Your answers are greatly appreciated! Thank you! ♥

This is labeled 'challenging problems' and I really need help with it...

The diagram shows a serial dilution of a stock solution !, from tubes A to B, then C and finally to D, in order to obtain various concentrations indicated below each tube. The initial volume of solution in tube A is 300 µl.

If the final volume in tube A must not be less than 200 µl, and tubes B and C at the end of the serial dilution is 100 µl,

i. what volume of stock solution Q is transferred into tube B?

ii. what volume of water is added to tube B?

iii. what is the final volume in tube D?

iv. what is the amount of stock transferred form the previous tube/µl in B, C and D?

v. what is the amount of water added/µl n B, C and D?

vi. what is the amount of diluted solution transferred out to the next tube/µl in A, B and C?

Then the question goes to show a diagram:

Tube A (60 mM) ----> tube B (30 mM) ---> tube C (15 mM) ---> tube D (7.5 mM)

Frankly, I don't understand what the (brackets) after the tube [letter] is. But mM stands for 'millimolar' if I'm not wrong. Please can anyone help? I don't mind it if you only answer one question--- all help will be appreciated! 10 points to best answer! I finally figured out how to VOTE BEST ANSWER. Haha.

I have a few Maths problems which I really don't get. Can anyone possibly help provide the solution? I really don't understand it. I'd ask my Mum, but I'm at a sleepover (I know; we're doing HOMEWORK at a sleepover) and my Dad's overseas. :(

1. If J = K(G-1/T), then T equals to K/GK-J... How is this so?

2. Jack and Jill each have a jug with 1L of water. The first day, Jack pours 1mL of water form his jug into Jill's. The second day, Jill pours 3mL of water from her jug into Jack's. The third day Jack pours 5mL from his jug into Jill's and so on, one of them pouring 2mL of water more than he or she got from the other the previous day. The volume, in millilitres, of water that Jack will have a the end of th 101st day is ______ (fill in the blank).

3.A train breaks down an hour after starting its journey. The engineer takes half an hour to make repairs, but the train can only continue at half its original speed and arrives at its destination 2 hours late. If the delay had occurred 100km further on in the journey, the train would only have been 1 hour late. The distance of the journey, in kilometres, was _____.

4. By placing a 1 at both ends of a number, the value is increased by 14 789. What is the sum of the digits of the original number?

5. A triangle PQR is to be formed having all sides of integer length. If PQ = 37 and QR = m, where m is a fixed integer less than 37, how many different lengths are possible for PR?

I know it's a lot, but honestly, I would love help. Even if you just answer one question. There are more questions, but I think I'll manage them by myself. But please help! ♥

Hey could I get some opinions, please, on this question:

-are vague memories more meaningful than vivid ones?

I just need opinions cos I enjoy having such a debate/Socratic seminar (note: this shouldn't be TOO hard cos I'm only 13, haha). :) But if you can I would love it if you gave points supporting both prop and opp. :D But don't trouble yourself TOO much. :)

Thanks! :)