Calculate the solar energy incident on a reflecting surface in one second

[Richie Smash]

Homework Statement

First I will say, I know I post here alot, but that is because I have exams coming up soon and I am a beginner, and It's crunch time, I'm self taught with only the help of friends and the internet. I'm currently doing a past examination as practice, but this one is much harder than the ones I've done before, and from every single post I've placed here, I have learned, I like how the helpers only give hints.

Ok without any further ado here is the question.

''A solar cooker focuses sunlight onto a pot containing food. The area of the reflecting surface is 0.75m² and the solar power incident on it is 800Wm^-2. Only 76% of the energy incident on the curved surface is reflected towards the pot.

Calculate:(i) The energy arriving at the curved surface each second.
(ii) the total energy reflected towards the pot in one hour

Homework Equations

KE=1/2*m*v²
W=J/S

The Attempt at a Solution

I would try to solve it but the problem is I don't have a time...
I'm thinking that ok the solar radiation is coming to the reflecting surface at 3.0*10⁸m/s but... That's all I have, I'm unfamiliar with this Watt per metre squared.

 

[kuruman]

A Watt is a Joule/second. 1 Watt/m² means that if you take a square that is 1 m on the side, then every second that goes by, one Joule worth of energy is incident on the surface. Here you are given the surface. In (i) you are asked to find how much energy hits the surface in one second. Do you think you can answer that?

 

[Richie Smash]

Ok I'm following a bit, that means in this question in one second 800 joules will hit a square 1m on the side.

But the area here is 0.75m²
So what I have to do is, 800 *0.75 and I will get 600Joules?

And now for one hour I would do 600*3600 and just simply find 76% of that and that is the answer.

 

[haruspex]

600*60

How many seconds in an hour?

As an aside, the question says the curved surface has an area of .75m². Presumably it means that is the cross-sectional area, i.e. the area of a flat surface with the same perimeter. Otherwise there is not enough information. We would need, e.g., the distance from mirror to pot.

 

[Richie Smash]

Ah yes my mistake 600*3600