Math Problem Statement

A rectangular piece of sheet metal has the width 50 π‘π‘š shorter than its length. From each corner, a 10 π‘π‘š Γ— 10 π‘π‘š square is cut out and the flaps are then folded up to form an open box. If the volume of the box is 104000 π‘π‘š3, find the length and width of the original piece of sheet metal.

Solution

Let's break down the problem step by step to find the dimensions of the original piece of sheet metal.

Step 1: Define variables

  • Let the length of the original piece of sheet metal be LL cm.
  • Let the width of the original piece of sheet metal be WW cm.

According to the problem, the width is 50 cm shorter than the length: W=Lβˆ’50W = L - 50

Step 2: Dimensions of the box

When a 10 cm Γ— 10 cm square is cut from each corner, the dimensions of the base of the resulting open box will be reduced by 20 cm (since 10 cm is cut from both sides of the length and width).

  • The new length of the box base will be Lβˆ’20L - 20 cm.
  • The new width of the box base will be Wβˆ’20=(Lβˆ’50)βˆ’20=Lβˆ’70W - 20 = (L - 50) - 20 = L - 70 cm.
  • The height of the box is the size of the square cut from the corners, which is 10 cm.

Step 3: Volume of the box

The volume of the box is given as 104,000 cmΒ³. The formula for the volume of a box is: Volume=lengthΓ—widthΓ—height\text{Volume} = \text{length} \times \text{width} \times \text{height}

Substitute the values for the length, width, and height of the box: 104000=(Lβˆ’20)(Lβˆ’70)(10)104000 = (L - 20)(L - 70)(10)

Step 4: Solve for LL

We can simplify the equation: 104000=10Γ—(Lβˆ’20)(Lβˆ’70)104000 = 10 \times (L - 20)(L - 70) 10400=(Lβˆ’20)(Lβˆ’70)10400 = (L - 20)(L - 70) Now expand the right-hand side: 10400=L2βˆ’70Lβˆ’20L+140010400 = L^2 - 70L - 20L + 1400 10400=L2βˆ’90L+140010400 = L^2 - 90L + 1400 Move all terms to one side of the equation: L2βˆ’90L+1400βˆ’10400=0L^2 - 90L + 1400 - 10400 = 0 L2βˆ’90Lβˆ’9000=0L^2 - 90L - 9000 = 0

Step 5: Solve the quadratic equation

We can solve the quadratic equation L2βˆ’90Lβˆ’9000=0L^2 - 90L - 9000 = 0 using the quadratic formula: L=βˆ’(βˆ’90)Β±(βˆ’90)2βˆ’4(1)(βˆ’9000)2(1)L = \frac{-(-90) \pm \sqrt{(-90)^2 - 4(1)(-9000)}}{2(1)} L=90Β±8100+360002L = \frac{90 \pm \sqrt{8100 + 36000}}{2} L=90Β±441002L = \frac{90 \pm \sqrt{44100}}{2} L=90Β±2102L = \frac{90 \pm 210}{2} This gives us two possible solutions: L=90+2102=3002=150L = \frac{90 + 210}{2} = \frac{300}{2} = 150 or L=90βˆ’2102=βˆ’1202=βˆ’60L = \frac{90 - 210}{2} = \frac{-120}{2} = -60

Since a negative length doesn't make sense, we discard L=βˆ’60L = -60 and keep L=150L = 150.

Step 6: Find the width

Using the relation W=Lβˆ’50W = L - 50: W=150βˆ’50=100W = 150 - 50 = 100

Final Answer:

  • The length of the original piece of sheet metal is 150 cm150 \, \text{cm}.
  • The width of the original piece of sheet metal is 100 cm100 \, \text{cm}.

Would you like further clarification or more details?

Here are some related questions you might find useful:

  1. How do we use the quadratic formula to solve real-world problems?
  2. What would happen if different-sized squares were cut from the corners of the sheet?
  3. How does the volume formula for a box apply to other geometric shapes?
  4. Can the height of the box be changed to achieve the same volume with different dimensions?
  5. How do changes in length and width affect the volume of a box?

Tip: Always check the physical feasibility of your solutions when solving equations in real-world problems.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Geometry

Formulas

Volume of a box = length Γ— width Γ— height
Quadratic equation: axΒ² + bx + c = 0
Relation between length and width: W = L - 50

Theorems

Quadratic Formula

Suitable Grade Level

Grades 9-11