Physical Quantities And Measurements Class 7 ICSE Physics | Selina Chapter 1 | Volume & Area #1

Deepika from Learn Hub introduces a free learning platform for studying subjects like physics, chemistry, and more. Today's session focuses on class seven physics, specifically on the chapter "Physical Quantities and Measurement." They began covering the basics of physical quantities and units in class six, discussing concepts like length, mass, time, and temperature.

In the class seven lesson, the focus shifts to volume, explaining that it's the space occupied by matter, with heat and matter having mass and occupying space. The concept of volume measurement and units, notably the SI unit cubic meters (m³), is introduced, with explanations on how to calculate the volume of different shapes like cubes and rectangular bricks.

The lesson dives deeper into measurements, explaining how to compute the volume of objects using their dimensions, like a cube being measured by its side length cubed, and how it's expressed in cubic meters or centimeters. Students learn to visualize how different objects occupy space and compare volumes using simple experiments with water rise levels.

Students are introduced to the use of measuring cylinders and beakers for determining liquid volumes, which are marked in milliliters and liters. An important lesson is understanding the meniscus and reading liquid levels accurately, mainly by viewing the lower surface of the meniscus at eye level.

Discussion proceeds to the measurement of volume for regular objects such as cubes, cuboids, spheres, cylinders, and cones, providing specific formulas for these shapes. Emphasis is made on ensuring unit consistency when calculating volume, converting units where necessary to maintain uniformity.

The class explores irregular solids' volume measurement using displacement methods, highlighting the practical process and connection to earlier teachings. Students learn to calculate water displacement caused by objects as an indirect but effective way of measuring their volume.

The video transitions to practical exercises involving volume questions, teaching how to solve for volume in both cubic centimeters and cubic meters using conversions. Real-life examples offer practical insight into applying mathematical formulas for real objects' dimensions.

Further exercises reinforce understanding by connecting volume measurement with liquid states like milk and water capacity calculations, using units familiar from daily life (liters and milliliters). The importance of understanding measurement conversions is a recurring theme.

New physical quantities are introduced, such as area, delving into geometric formulas for determining the area of squares, rectangles, circles, and more. As with volume, students learn to ensure consistency in units and practice calculations for both large and small areas.

Students learn to use graph papers to measure the area of irregular objects by counting square units on a graph directly, reinforcing the practical application of theoretical knowledge.

More complex problems are tackled, illustrating the application of the formulas to real-world problems, providing examples of how these can be used beyond the classroom in everyday scenarios and fields such as engineering and architecture.

The lesson reiterates the need to practice conversion and formula application, ensuring students are comfortable with switching between unit systems and applying them to various mathematical problems.