Q1 A cubical box has each edge 10 cm and another cuboidal box is 12.5 cm long, 10 cm wide and 8 cm high. (i) Which box has the greater lateral surface area and by how much? (ii) Which box has the smaller total surface area and by how much?
Part (i): The lateral surface area of a cubical box is given by the formula 4a^2, where a is the length of each edge of the cube . Substituting a=10 cm, we get the lateral surface area of the cubical box as 4*10^2 = 400 cm^.
The lateral surface area of a cuboidal box is given by the formula 2h(l+b), where h, l, and b are the height, length, and breadth of the cuboid, respectively 1. Substituting h=8 cm, l=12.5 cm, and b=10 cm, we get the lateral surface area of the cuboidal box as 2*8*(12.5+10) = 440 cm^.
Therefore, the cuboidal box has a greater lateral surface area than the cubical box by (440-400) = 40 cm^.
Part (ii): The total surface area of a cubical box is given by the formula 6a^2, where a is the length of each edge of the cube . Substituting a=10 cm, we get the total surface area of the cubical box as 6*10^2 = 600 cm^.
The total surface area of a cuboidal box is given by the formula 2(lb+bh+hl), where h, l, and b are the height, length, and breadth of the cuboid, respectively . Substituting h=8 cm, l=12.5 cm, and b=10 cm, we get the total surface area of the cuboidal box as 2*(12.5*10 + 10*8 + 8*12.5) = 610 cm^.
Therefore, the cubical box has a smaller total surface area than the cuboidal box by (610-600) = 10 cm^2.
Answers & Comments
Answer:
Let’s solve this problem step by step.
Part (i): The lateral surface area of a cubical box is given by the formula 4a^2, where a is the length of each edge of the cube . Substituting a=10 cm, we get the lateral surface area of the cubical box as 4*10^2 = 400 cm^.
The lateral surface area of a cuboidal box is given by the formula 2h(l+b), where h, l, and b are the height, length, and breadth of the cuboid, respectively 1. Substituting h=8 cm, l=12.5 cm, and b=10 cm, we get the lateral surface area of the cuboidal box as 2*8*(12.5+10) = 440 cm^.
Therefore, the cuboidal box has a greater lateral surface area than the cubical box by (440-400) = 40 cm^.
Part (ii): The total surface area of a cubical box is given by the formula 6a^2, where a is the length of each edge of the cube . Substituting a=10 cm, we get the total surface area of the cubical box as 6*10^2 = 600 cm^.
The total surface area of a cuboidal box is given by the formula 2(lb+bh+hl), where h, l, and b are the height, length, and breadth of the cuboid, respectively . Substituting h=8 cm, l=12.5 cm, and b=10 cm, we get the total surface area of the cuboidal box as 2*(12.5*10 + 10*8 + 8*12.5) = 610 cm^.
Therefore, the cubical box has a smaller total surface area than the cuboidal box by (610-600) = 10 cm^2.