Using Pythagoras theorem, the top of the ladder moving down when the foot of the ladder is 3 feet from the wall is of -0.518 feet/sec.
Let distance from the wall to the foot of the ladder is 'x' feet and the height of the top of the ladder is 'y' feet.
Pythagoras theorem,
--->(1)
Given,
at x=3
Put x=3 in Pythagoras theorem equation (1)


= 135
y = 11.61
Derive equation (1) w.r.t to 't'
---->(2)
substitute the value of 'x', 'dx/dt' and 'y' in equation (2), we get the fast of the top of the ladder moving down when the foot of the ladder is 3 feet from the wall
12 + 23.22
= 0


Hence, using Pythagoras theorem the top of the ladder moving down when the foot of the ladder is 3 feet from the wall is of -0.518 feet/sec.
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Answer:
24 1/2
Step-by-step explanation:
Answer:
So, the required width of rectangular piece of aluminium is 8 inches
Step-by-step explanation:
We are given:
Perimeter of rectangular piece of aluminium = 62 inches
Let width of rectangular piece of aluminium = w
and length of rectangular piece of aluminium = w+15
We need to find width i.e value of x
The formula for finding perimeter of rectangle is: 
Now, Putting values in formula for finding Width w:

After solving we get the width of rectangular piece :w = 8
So, the required width of rectangular piece of aluminium is 8 inches
Yes, the volume it is 8³ = 512
The volume it is 420
512 >>> 420
The side the cube is ³√420 = 7.48 in
8 >> 7.44