Sorry, I figured it out... both are biconvex lenses therefore their focal lengths are positive. I believe I got confused with radius' of curvatures.. the solution given is the correct one.
Homework Statement
A biconvex lens, L_1, with focal length of magnitude \left|
f_1
\right|
= 15 cm is used with a second biconvex lens, L_2, with focal length of magnitude \left|
f_2
\right|
= 25 cm to form a compound lens system.
If the two lenses are placed in mutual contact what is...
Hi there SteamKing. I will use the Jacobian when I evaluate the integral.
## \int_{r_1}^{r_2} \int_{\theta_1}^{\theta_2} \int_{z_1}^{z_2} r \ dz d{\theta} dr ##
something like that.
Homework Statement
Using a suitable Jacobian, evaluate the volume bounded by the surface ##z = 2 +x^2##, the cylinder ##x^2 + y^2 = a^2## (where ##a## is a constant), and the ##x-y## plane.
Homework Equations
##x = r cos{\theta} ##
##y = r sin{\theta} ##
The Attempt at a Solution
I...
Homework Statement
A lamina is bounded by the x-axis, the y-axis, and the curve ##y = 4 -x^2.## Determine the centroid position ##(\bar{x},\bar{y})## of the lamina.
Homework Equations
## A = \int_a^b (f(x) - g(x)) dx ## (Area)
##\bar{x} = \frac{1}{A}\int_a^b x(f(x) - g(x)) dx ##
##\bar{y}...
Homework Statement
A wave traveling along a long string has the form:
##y(x,t) = 20sin(3x - 2t),
## where ##x## is in metres and ##t## is in seconds.
Find the amplitude of the velocity of any particle of the string.
2. Homework Equations
Do I just find ##\frac {\partial y}{\partial t}...
Oh, the T is the tension of the string, which is upwards. How would I go about this? It's true I would rather know the method so I can apply the method again in the future.