How long does it take the Sun to melt a block of ice

itryphysics
Messages
114
Reaction score
0

Homework Statement


How long does it take the Sun to melt a block of ice at 0 celcius with a flat horizontal area 1.0 m^2 and thickness 1.0 cm ? Assume that the Sun's rays make an angle of 30 with the vertical and that the emissivity of ice is 0.050.



Homework Equations



delta [Q] / delta [t] = (1000W/m^2)(emissivity)A(cos theta)


The Attempt at a Solution



delta [Q] / delta [t] = 1000(.05)(cos30)

I know that this does not give me time. I don't know how to manipulate this equation..please help . Thanks!
 
Physics news on Phys.org


What should ΔQ be, in order to melt a block of ice of the given volume?
 

Thread 'Please tell me where I am going wrong in this integral'

##|\Psi|^2=\frac{1}{\sqrt{\pi b^2}}\exp(\frac{-(x-x_0)^2}{b^2}).## ##\braket{x}=\frac{1}{\sqrt{\pi b^2}}\int_{-\infty}^{\infty}dx\,x\exp(-\frac{(x-x_0)^2}{b^2}).## ##y=x-x_0 \quad x=y+x_0 \quad dy=dx.## The boundaries remain infinite, I believe. ##\frac{1}{\sqrt{\pi b^2}}\int_{-\infty}^{\infty}dy(y+x_0)\exp(\frac{-y^2}{b^2}).## ##\frac{2}{\sqrt{\pi b^2}}\int_0^{\infty}dy\,y\exp(\frac{-y^2}{b^2})+\frac{2x_0}{\sqrt{\pi b^2}}\int_0^{\infty}dy\,\exp(-\frac{y^2}{b^2}).## I then resolved the two...
View full post »

Thread 'Direction of the magnetic field of an oscillating charge'

Hello everyone, I’m considering a point charge q that oscillates harmonically about the origin along the z-axis, e.g. $$z_{q}(t)= A\sin(wt)$$ In a strongly simplified / quasi-instantaneous approximation I ignore retardation and take the electric field at the position ##r=(x,y,z)## simply to be the “Coulomb field at the charge’s instantaneous position”: $$E(r,t)=\frac{q}{4\pi\varepsilon_{0}}\frac{r-r_{q}(t)}{||r-r_{q}(t)||^{3}}$$ with $$r_{q}(t)=(0,0,z_{q}(t))$$ (I’m aware this isn’t...
View full post »

Thread 'Initial conditions for orbits around a wormhole'

Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
View full post »

Similar threads

Calculate the latent heat of fusion of ice
Replies
6
Views
3K
Calculate how long it will take for the ice to melt?
Replies
1
Views
65K
Heat Transfer Coefficient for Ice Melting Time
Replies
1
Views
10K
Thermal Conductivity - Forming ice under water
Replies
1
Views
2K
How long will the sun burn if only combustion is happening.
Replies
1
Views
3K
I How Long Does Water Ice Take to Sublimate in Space?
Replies
7
Views
3K
Heat transfer, how long it takes ice to reach melting point
Replies
6
Views
4K
How does the loss of sea ice affect Earth's temperature?
Replies
42
Views
8K
How Does a Steel Bar Sink Through Ice?
Replies
2
Views
4K
Calculating how long it takes for a comet to reach a sun of radius zero
Replies
9
Views
3K

Hot Threads

Recent Insights

Back
Top