150 degrees should give more radians than 120 degrees. It's just measured on a different scale so that shouldn't cause it to become negative.
Try using google if the conversion isn't working out too well.
Angular velocity is rate of change of angle about a fixed point, so if it's negative it means you're now moving around the point in the opposite direction.
Using the uncertainty principle for energy and time, estimate the range of the Strong interaction if it is due to the exchange of a pion with rest mass 140GeV (Take the value of h as 4.14x10^-21MeV s)
Now I know that Delta T x Delta E is > or = to hbar
and that I want DeltaX as a solution. But...
I was set a problem describing a series of 6 slits, spacing of 0.4mm and diffracting light of wavelength 600nm onto a screen 4m away. I had to graph the intensity across the screen. Now I managed that ok, but then it wants to now how the resulting graph would change if the slits had finite width...