A cylindrical gasoline can is 18 inches across and 20 inches tall. which expression represents the approximate volume in cubic inches ?
1) (3.14)(9)2(20)
2) (3.14)(9)(20)2
3) (3.14)(18)(20)
4) (3.14)(18)2(20)
5) (3.14)(36)2(20)
V = pi * r^2 * h
Which of your answers expresses that formula?
number 4
No. The radius is not 18.
the answer is
5
Nope. The radius is half the diameter.
To calculate the volume of a cylindrical object, you need to use the formula V = πr²h, where V represents the volume, π is a mathematical constant approximately equal to 3.14, r is the radius of the base (half the diameter), and h is the height of the cylinder.
In this case, the diameter of the gasoline can is given as 18 inches, which means the radius is half of that, or 9 inches. The height of the cylinder is given as 20 inches.
To find the volume, simply substitute the given values into the formula:
V = π(9)²(20)
Now we need to simplify the expression to find the approximate volume of the gasoline can in cubic inches. Let's go through each option to see which one matches the correct way to simplify the expression:
1) (3.14)(9)²(20) - This expression is correct because it follows the order of operations, first calculating the square of the radius and then multiplying by π and the height.
2) (3.14)(9)(20)² - This expression is incorrect because it incorrectly calculates the square of the height instead of the radius.
3) (3.14)(18)(20) - This expression is incorrect because it directly multiplies the diameter (18) instead of halving it to get the radius (9).
4) (3.14)(18)²(20) - This expression is incorrect because it incorrectly squares the diameter (18) instead of the radius (9).
5) (3.14)(36)²(20) - This expression is incorrect because it uses the diameter (36) instead of the radius (9), and also incorrectly squares the diameter instead of the radius.
Therefore, the correct expression that represents the approximate volume in cubic inches is option 1) (3.14)(9)²(20).