Recent content by Gammage

Studying for a Modern Physics final and a discussion question from an old test is bugging me. How would the universe be different if the mass of the electron was the same as the mass of the proton? First thing that comes to my mind is density of materials and electronics, but I don't think I...

I am having trouble understanding this problem. It has several parts describing a binary star system. The last part ask for the apparent magnitude of the combined light from both stars, if they were viewed as a single point. I guess my first thought was to add them, but I'm worried because...

Thanks! I understand it now.

(\stackrel{11}{5}) odd and (\stackrel{10}{6}) even?

Homework Statement Let l, m, and n be positive integers with l \leq m and l \leq n. Prove the identity. (\stackrel{m + n}{l}) = (\stackrel{m}{0})(\stackrel{n}{l}) + (\stackrel{m}{1})(\stackrel{n}{l-1})+...+(\stackrel{m}{l})(\stackrel{n}{0}) 2. The attempt at a solution I have no clue, I...

Homework Statement How many subsets S \subseteq {1,2,...,21} are there if S is required to contain 5 odd integers and 6 even integers? 2. The attempt at a solution I am having trouble breaking this one down. If the subsets contain 5 odd and 6 even, do they only contain 5 odd and 6 even...

Homework Statement A bullet of mass 4 g moving with an initial speed of 300 m/s is fired into and passes through ta block of mass 5kg. The block, initially at rest on a frictionless horizontal surface, is connected to a spring of force constant 600 N/m. If the block moves a distance of 1.6...

Thanks, that helped a lot. I found the change in the x component of the momentum then divided by the time.

The book The Golden Section: Nature's Greatest Secret by Scot Olsen is all about the subject. It is a very light read. You could probally finish it one afternoon at a bookstore.

A 9 kg steel ball strikes a wall with a speed of 10 m/s at an angle of 49.8 degrees with the normal to the wall. It bounces off with the same speed and angle. If the ball is in contact with the wall for .0911 sec, what is the magnitude of the average force exerted on the ball by the wall...

the 1x10^-11 is mentioned in the problem as delta g divided by g. when I set g = 1x10^-11 and M = 78kg, and solved for r the answer is wrong.

Hmm, there is a very brief explanation in the chapter we are in showing that the field is equal to G(M)/r^2, which is simular to what i did before but this would give me N/kg, do i factor his mass in again to get some cancelations?

Very Little I don't think we have discussed yet in class, let me check the book for any references. This is a first year Mechanics course for natural science majors.

Homework Statement A superconducting gravity meter can measure changes in gravity of the order = 1×10-11 (delta g)/g. You are hiding behind a tree holding the meter, and your 78 kg friend approaches the tree from the other side. How close to you can your friend get before the meter detects a...