Amin

1. Cộng đồng
2. Study Group
3. Dividing by 2pi on a scientific calculator?

You need to be aware of what exactly is in the numerator and denominator, and then type the values into the calculator accordingly. For the fraction 1/2pi, you will get different answers if pi is b...

1. Cộng đồng
2. Study Group
3. Faster than light?

I think the best way to understand both of these concepts, is to first move away from Newton's view of gravity and understand it from Einstein's perspective. Einstein's theory of gravity is general...

1. Cộng đồng
2. Study Group
3. Adding Vectors

Just to point something out for anyone who passes by this thread, the "A+B" in the images is just referring to the fact that vector A and vector B have to be combined, and that when added appropria...

1. Cộng đồng
2. Content Requests and Feedback
3. Chemistry Redox Reactions

Hi Maia, I'm not sure exactly what is meant by the "acid reaction" or the base formula; I may have learned this slightly differently, but I'll go through how I was able to solve this (can't be that...

1. Cộng đồng
2. Study Group
3. Biology

Hi Kimm, The molecule adenosine triphosphate, or ATP, is typically understood as the "energy currency" of biological processes.  ATP is a high-energy molecule that transfers and releases energy nee...

1. Cộng đồng
2. Study Group
3. stars and light

If you're at such a great distance from the star that the star's light hasn't had time to reach you since it formed, then yes, you would not see it :] If you wait long enough you will be able, at l...

1. Cộng đồng
2. Study Group
3. binomial theorum and pascal's triangle

When you evaluate the binomial using Pascal's triangle, you have to remember to substitute the terms and their signs within parentheses. So, while the statement -p^0 = -1 is true, it is used incorr...

1. Cộng đồng
2. Study Group
3. Trigonometry: Pythagorean Identities

If sin theta = 3/4, then theta = sin^-1(3/4) = 0.84806207898148... By the identity sin theta = sin(pi - theta), theta can also be 2.29353057460831... Even though neither answer can be written as a ...

1. Cộng đồng
2. Study Group
3. how can gravity wrap space-time when space itself is not a sheet but a volume

Gravity doesn't warp spacetime.  Gravity is warped spacetime.  Mass causes spacetime to warp in its presence; therefore, mass gives rise to gravity. The familiar analogy that many use is the two-di...

1. Cộng đồng
2. Study Group
3. Universe growing

The universe is expanding, yes, but more matter is not being created to fill in the gaps.  As a consequence of this, the universe's density decreases over time. The idea that more matter had to be ...