What Is the Area of the Largest Rectangle Inscribed in a Semicircle?

AI Thread Summary
The area of the largest rectangle inscribed in a semicircle with radius r is calculated using the formula A = r^2. To derive this, one can express one side of the rectangle in terms of the other, establishing a relationship between height and width. By drawing the semicircle and the inscribed rectangle, the dimensions can be analyzed to find the maximum area. The critical point is that knowing one dimension allows for the calculation of the other. Understanding these relationships is essential for solving the problem effectively.
thegame
Messages
32
Reaction score
0
What is the area of the largest rectangle that can be inscribes indiside a semicircle with the radius r?

answer: x = r / SQRT(2)
A = r^2
 
Physics news on Phys.org
Is there a question here?
 
How do you ge the answer?
 
How did YOU get the answer?
 
Well, if you know one side of a rectangle inscribed in a semicircle, can you figure out the other side?
 
What Hurkyl's getting at is:

Draw the semicircle. Draw a rectangle inside it, call one side h, call the other side w, call the radius r.

Now find a relationship that let's you eliminate either h or w. In other words, express h as a function of w, or w as a function of h.
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
I was thinking using 2 purple mattress samples, and taping them together, I do want other ideas though, the main guidelines are; Must have a volume LESS than 1600 cubic centimeters, and CAN'T exceed 25 cm in ANY direction. Must be LESS than 1 kg. NO parachutes. NO glue or Tape can touch the egg. MUST be able to take egg out in less than 1 minute. Grade A large eggs will be used.
Back
Top