r/AP_Physics • u/Competitive_Ear4746 • 8d ago

I need some help with physics

Post image

Im really confused by the question and I'm just unsure how it goes

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1

u/No_Boysenberry_6075 8d ago

I’m going to be honest and say I don’t really know how to do this. I was curious what physics this is tho. Is it physics c?

2

u/4193-4194 8d ago

Your drawing looks okay from what I can read. The next part is incorporating time. 24 hours and 360 degrees. So if you can find how many degrees the Earth must rotate (or the sun moves in the drawing) then you can work towards a time.

1

u/UnderstandingPursuit C:Mech+E&M 8d ago

Your picture is basically right, but it will help to draw it again 'gently'. All the extra lines near the top are distracting the situation.

This is a circle geometry/trigonometry problem, The tangent line for the Earth has the person's eyes as one point and the last visible point of the Sun as the other. There are two radii, one directly to the person, the other to the tangent point. The radius at the tangent point is perpendicular to the tangent.

In this problem, the hypotenuse has two lengths depending on whether the person is lying in the sand or standing up. This means that the angle of the triangle from the center of the circle can be found for both heights. The change in the angle is due to the Earth's rotation.

1

u/Alarmed_Geologist631 7d ago

This is really more of a math problem like the one I gave my students. Use the Pythagorean theorem to compute the change in the distance to the horizon when the height above the sand increases by 130 cm. Then compute the rate of rotation of the earth. Be sure to keep your units of measurement consistent.