Answer:1.69*10^12 J
Step-by-step explanation:
From figure above, using triangle ratio
485/755.5=y/l. Cross multiplying 485l=755.5y Divide via 485) hence l= 755.5y/485
Consider a slice volume Vslice= (755.5y/485)^2∆y; recall density =150lb/ft^3
Force slice = 150*755.5^2.y^2.∆y/485^2
From figure 2 in the attachment work done for elementary sclice
Wslice= 150.755.5^2.y^2.∆y.(485-y)/485^2
= (150*755.5^2*y^2)(485-y)∆y/485
To calculate the total work we integrate from y=0 to y= 485
Ie W=[ integral of 150*755.5^2 *y^2(485-y)dy/485] at y=0 and y= 485
Integrating the above
W= 150*755.5^2/485[485*y^3/3-y^4/4] at y= 0 and y=485
W= 150*755.5^2/485(485*485^3/3-484^4/4)-(485.0^3/3-0^4/4)
Work done 1.69*10^12joules
Hi there!
For any 45 45 90 right triangle, the length of the hypotenuse is always the square root of 2 times one of the legs.
To get the lengths of the leg, let's divide the length of the hypotenuse by the square root of 2.
We get the following:

When simplifying fractions like this, we want to avoid having radicals on the bottom. In order to remove the radical from the denominator, let's multiply the numerator and the denominator by the square root of 2.
We get the following:

That's your answer.
Have an awesome day! :)
- collinjun0827, Junior Moderator