# Search results

1. ### Calculate Deutron Mass Given Binding Energy

Homework Statement The deuteron is a bound state between a proton and a neutron (and the nucleus of the H2 isotope). The binding energy of the deuteron is 2.2MeV. What is the mass of the deuteron? Homework Equations Mp = 938.3 MeV/c^2 Mn = 939.6 MeV/c^2 The Attempt at a Solution...
2. ### Parallel plate capacitor with a dielectric?

If you have a simple circuit with only a battery and a parallel plate capacitor with a dielectric, what exactly happens when the battery is turned on? Also, if the voltage of a capacitor with a dielectric is less than the EMF of the battery, what happens to the rest of the voltage? One...
3. ### Trigonometric Substitution

I was messing around proving the area of a circle using trigonometric substitution. However, I ended up with area = -πr^2. In my integral I ended up using trigonometric substitution and setting x = r*cos(theta) However, this yields x = -r*sin(theta)*d(theta). When that's substituted...
4. ### Question about directional derivatives and tangent planes ?

Is it possible to find a directional derivative for a point on z = f(x,y) at a point (x,y) in a direction (u1,u2) using the plane tangent to z at (x,y)? If so, how? Thanks!
5. ### Binary-star system, gravity + centripetal force question?

1. In a certain binary-star system, each star has the a mass of 1.36e30 kg, and they revolve about their center of mass. The distance between them is 1.1e8 km. What is their period of revolution in Earth years? 2. gravity = centripetal force (g*m*m)/d^2 = (mv^2)/r 3. I've tried plugging...
6. ### Energy: Block sliding down frictionless ramp

1. In Figure 8-49, a block is sent sliding down a frictionless ramp. Its speeds at points A and B are 1.90 m/s and 2.60 m/s, respectively. Next, it is again sent sliding down the ramp, but this time its speed at point A is 3.85 m/s. What then is its speed at point B? Figure 8-49...
7. ### Derivitives of functions

1. Find the value of (f o g)^1 at the given value of x. f(u) = 1-(1/u) u = g(x) = 1/(1-x) x = -1 2. Chain rule... 3. Okay, so the derivitive of 1-(1/(1/(1-x))) is 1. Also, the derivitive of 1/(1-x) = 1/(x-1)^2. So, in theory, shouldn't the answer be 1/4? I've solved this in...
8. ### Very Simple Forces Question

Homework Statement Four firefighters hold a square net, one at each corner. Each person exerts a force of 190 N whose line-of-action passes through a point just below the center of the net and makes an angle with the vertical of 50°. What is the net force the firefighters exert on the net...