Volume is the amount of space that can be shaded in an object whereas density is the mass of the object per unit volume. You need to know the volume of an object before you can calculate its density. The volume of an ordinary object can be calculated using a simple formula determined by the shape of the object. The standard unit for volume is the cubic centimeter (cm3), cubic meters (m3). If you know the volume value, the density of the object can already be calculated. The standard unit of density is grams per cubic centimeter (g/cm3) or grams per milliliter (g/mL).
Step
Part 1 of 3: Calculating the Volume of Ordinary Objects
Step 1. Define the shape of your object
The formulas and measurements used to calculate the volume of an object depend on the shape of the object.
- Form ball is a perfectly circular three-dimensional object in which every point on its surface is equidistant from its center.
- Form cone is a 3-dimensional shape that has a circular base and a vertex (conical tip). Just think of a cone as a pyramid with a circular base.
- Form Cube is a 3-dimensional shape that has six square faces that are exactly the same.
- Form beam, also known as a rectangular prism, is similar to a cube in that it has 6 faces. However, the sides of the blocks are rectangles, instead of squares.
- Form cylinder is a 3-dimensional shape that has two ends in the shape of a circle of exactly the same size, and a curved side connecting the two.
- Form pyramid or pyramid is a 3-dimensional shape that has a polygon as a base, and sides that taper at one point (the tip of the pyramid). A regular pyramid is a pyramid whose base is a regular polygon, meaning that all the sides of the polygon are the same length and all the angles are the same.
- If the object has an unusual shape, you can use the displacement method to measure volume
Step 2. Choose the right equation
Each shape has its own volume formula. Below are the formulas for each of the shapes mentioned above. Please read How to Calculate Volume for more information.
- Ball: V=43πr3, {displaystyle V={frac {4}{3}}\pi r^{3}, }
yaitu r adalah radius bola.
- Kerucut: V=13πr2t, {displaystyle V={frac {1}{3}}\pi r^{2}t, }
- Kubus: V=r3, {displaystyle V=r^{3}, }
- Balok: V=plt, {displaystyle V=plt, }
- Silinder: πr2t, {displaystyle \pi r^{2}t, }
- Piramida: V=13Lt, {displaystyle V={frac {1}{3}}Lt, }
yaitu r adalah radius lingkaran pada dasar kerucut dan t adalah tinggi kerucut.
yaitu r adalah panjang rusuk kubus.
yaitu p adalah panjang sisi persegi panjang, l adalah lebar persegi panjang, dan t adalah tinggi balok.
yaitu r adalah radius dasar lingkaran dan t adalah tinggi silinder.
yaitu L adalah luas alas dasar piramida dan t adalah tinggi piramida
Step 3. Take the necessary measurements
The measurements taken depend on the shape of your object. on most objects, you need to know the size of the height. However, if the shape involves a circle, you will only need the radius.
- The radius of a circle is half its diameter. Measure the diameter by placing a ruler exactly along the middle of the circle and looking at the number. Divide the diameter by 2 to get the radius.
- Finding the radius of the sphere takes some extra work, but there are several ways to get it.
- The length, width, and height of the object can be obtained with a ruler starting from one end of the object to the other end. After that, look at the numbers on the ruler.
Step 4. Calculate the volume
If the shape of the object, the formula used, and the measurements have been determined, the volume can be calculated. Just plug the numbers you measured earlier into the appropriate formula and calculate the results to get the volume.
Don't forget to mark the answer with cubic units. Whichever metric is used, the unit of volume is always in cubics
Part 2 of 3: Calculating Unusual Object Shapes
Step 1. Calculate the volume of the object using the displacement method
Objects of irregular shape are difficult to count and often inaccurate volume results are obtained. By measuring the amount of water displaced by an object, you can easily determine the volume of an object without using complicated formulas
This method can also be used to determine the volume of a regular shape
Step 2. Fill the graduated cylinder with water
A measuring cylinder is a laboratory device that has a size marker on its outer surface and allows you to measure the volume of a liquid. Make sure the measuring cylinder is large enough to accommodate your object. The object will need to be completely submerged in the cylinder, but not spilled. Record the initial volume of water in the beaker.
When you record the initial water volume, make sure you look at the water at eye level and note the number at the base of the meniscus. The meniscus is a curve in water when it comes into contact with another surface
Step 3. Slowly insert the object into the beaker
You can't drop the water because it will squirt out later. Make sure your object is completely submerged. Record the new water level in the beaker at eye level and pay close attention to the meniscus.
If any water is spilled when the object is inserted, repeat with a larger measuring cylinder or reduce the water
Step 4. Subtract the new water level from the initial water level
The amount of water displaced by the object is equal to the volume of the object in cubic centimeters. Liquids are usually measured in milliliters. One milliliter is equal to one cubic centimeter.
- For example, if your initial water volume is 35 mL and the final water volume is 65 mL, the volume is 65 – 35 = 30 mL or 30 cm3
Part 3 of 3: Calculating Density
Step 1. Determine the mass of the object
The amount of matter in an object is equal to the mass of that object. Mass is measured directly by weighing the object using a scale. The unit of mass is grams.
- Find an accurate scale and place an object on it. Record the numbers in your book.
- You can also measure mass with a balance. Place the object on one side and place the numbered weight on the other until both sides of the scale are balanced. The mass of the object is equal to the total mass of the ballast.
- Objects must be dry before weighing. This ensures that no water is absorbed that could interfere with measurement accuracy.
Step 2. Calculate the volume of your object
if the object has a regular shape, please find the volume using the formulas above. If the shape is unusual, use the transfer method also detailed above.
Step 3. Calculate the density of the object
Density is defined as mass divided by volume. To complete our calculation, divide the mass you measured and the volume you previously calculated. The result is the density of the object measured in g/cm3.
- For example, calculate the density {displaystyle \rho }
suatu zat yang volumenya 8 cm3 dan massa 24 g.
- ρ=mv=24 g8 cm3=3 g cm−3{displaystyle {begin{aligned}\rho &={frac {m}{v}}\\&={frac {24{rm { g}}}{8{rm { cm^{3}}}}}\\&=3{rm { g\ cm^{-3}}}\end{aligned}}}
tips
- anda bisa menguji perhitungan volume menggunakan metode pemindahan dan membandingkan hasilnya.
- objek sering kali merupakan gabungan objek geometri lain. jadi, uraikan objek menjadi kelompok bentuk-bentuk dasar kecil dan temukan volumenya satu per satu. setelah itu, jumlahkan semuanya untuk memperoleh total volume objek.