SummaGirl

This is my last question for my pre-calc homework and I have no idea how to solve this problem:

In physics, a radioactive decay is a process in which an unstable atom spontaneously emits particles and radiation. Suppose a radioactive amount of Radium R that is present after t years is given by the formul R=Pe^(−kt) , where P represents the number of grams present initially and k is a constant. Find k if 30% of radium disappears after 100 years.

If you know the answer or just the formula, that would be a huge help!

So basically yesterday my guy friend called me a rock and said it would be impossible to break through the wall that's in my head. We were with a group of friends when he said this and they all agreed. At the time, I was just like whatever. But the more I think about it, the more I want to know what it means.

Does that seem kinda harsh, or am I being too sensitive? What does it mean?

So I've had this feeling all along, I've been crushing on him for months, and always hoped he might like me more than just a friend, but I think I always knew deep down he didn't. I just realized that tonight. And now I feel like complete crap.

How do I move on from this, especially if nothing is going to happen? This feeling sucks, I just want to be over it.

So there's this guy I really like, and we've started to become good friends. I've had a crush on him for months, and it feels like just in the last week we've started talking a lot more, he's messaged me on fb when he didn't see me last week, he's always teasing me, ext.. But the problem is, he leaves for college in January, so basically I probably have maybe 2 or 3 weeks left with him, which is less because of the holidays.

I don't know what to do, I really like him, but I don't want to put myself out there just to be rejected, that would be horrible. Should I just not even bother with him since he's leaving and let it go? I just could really use some unbiased advice.

So at this fitness group I go to, there's this guy that I have a crush on and I know it would never work out for many different reasons 1) he's not even my type 2) i'm 18 and he's 21 3) he's transferring schools and leaving in January and 4) since I'm the only girl out of the group I don't want to give the impression I'm boy crazy since all the boys are all really good friends. And I just can't get over him. I'm close to all the other guys in the group, but him, so I don't know why I have this crush on him. And as corny as it sounds, I dream about him at night too. Like, when I think about him leaving in a few weeks I get really depressed and it just annoys me because I'm not that type of girl.

Plus I don't even know if he likes me back. Again, I'm really good friends with all the other guys BUT him. We talk occasionally, it's not like he doesn't know I exist. It's just, he seems really shy around me compared to how he acts with the other guys. I do catch him staring at me, but when I look at him, he just looks away. And if he does talk to me, he's usually making some smartass comment. He's just so confusing and it's been like this for months.

I know this question is probably ridiculous, but how do I get over him and get rid of these feelings? I just want to feel normal again. Thanks to everyone who answers!