Math Case Study on Exponents and Powers for Class 8

Math Case Study on Exponents and Powers for Class 8

The Math Case Study on Exponents and Powers for Class 8 explains how powers and laws of exponents are used to simplify large numbers. Moreover, it strengthens the foundation for algebraic expressions and scientific calculations in higher grades. Students can explore practical problems and real-life applications through this engaging topic.

Key Concepts of Exponents and Powers

In this chapter, you will learn about laws of exponents, power of a power, and standard form representation. Additionally, case study questions are designed according to the CBSE Class 8 Maths syllabus and follow NCERT guidelines to ensure clarity and accuracy.

Video Tutorial and Practice Resources

Watch our video tutorial on Exponents and Powers to improve understanding. Furthermore, download Class 8 Maths case study PDFs with step-by-step solutions to build confidence and accuracy in solving exam-based questions effectively.

Satellite Communication and Scientific Notation Case Study

Case Study 5: Math Case Study on Exponents and Powers for Class 8

In modern communication systems, satellites play a crucial role in transmitting signals across vast distances. These satellites orbit the Earth at heights that are often expressed in scientific notation because the values involved are extremely large. For instance, a geostationary satellite orbits approximately \(3.6 \times 10^7\) meters above the Earth’s surface. Engineers also work with very small numbers such as the wavelength of the signal, which might be around \(2.5 \times 10^{-2}\) meters. While designing systems, engineers must use the laws of exponents to simplify calculations involving frequency, power, and signal strength. The use of powers of 10 helps in maintaining accuracy and ease in computation. Understanding and applying exponent rules and scientific notation ensures that data transmission remains precise and efficient in real-world applications like GPS, television broadcasting, and internet communication.

MCQ Questions:

1. The height of a geostationary satellite is \(3.6 \times 10^7\) m. The wavelength of a signal is \(2.5 \times 10^{-2}\) m. What is the ratio of the height of the satellite to the wavelength of the signal?
Solution:
\[ \frac{3.6 \times 10^7}{2.5 \times 10^{-2}} = 1.44 \times 10^{(7 – (-2))} = 1.44 \times 10^{9} \]
2. The power of a signal is given by \(5 \times 10^{-3}\) W and is amplified by \(2 \times 10^{3}\) times. What is the new power of the signal?
Solution:
\[ (5 \times 10^{-3}) \times (2 \times 10^{3}) = 10 \times 10^{0} = 1.0 \times 10^{0} \text{ W} \]
3. The distance between two satellites is \(2.4 \times 10^5\) m and the average signal speed is \(3 \times 10^8\) m/s. How much time (in seconds) does the signal take to travel between them?
Solution:
\[ t = \frac{\text{distance}}{\text{speed}} = \frac{2.4 \times 10^5}{3 \times 10^8} = 0.8 \times 10^{-3} = 8.0 \times 10^{-4} \text{ s} \]
4. A satellite transmits signals with a power of \(1.2 \times 10^5\) W. If the signal power decreases to \(3 \times 10^{-3}\) of its value when it reaches Earth, what is the received power?
Solution:
\[ 1.2 \times 10^5 \times 3 \times 10^{-3} = 3.6 \times 10^{2} \text{ W} \]
5. A satellite is \(3.6 \times 10^7\) m above Earth and another is \(7.2 \times 10^7\) m. Find the ratio of their altitudes in simplest form.
Solution:
\[ \frac{3.6 \times 10^7}{7.2 \times 10^7} = \frac{1}{2} \Rightarrow 1 : 2 \]
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