Share & grow the world's knowledge!
We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge.
Rohan studies science from 6 PM to 7:30 PM at home. Consider the tip of the minute’s hand of the wall clock. During the given time interval, what is its: (i) distance travelled, (ii) displacement, (iii) speed and (iv) velocity. The length of the minute’s hand is 7 cm (Fig. 4.32).
The minute hand has radius 7 cm and moves for 90 minutes = 5400 s. It completes 1.5 revolutions. Therefore, distance = 1.5 × 2π × 7 = 21π cm ≈ 66 cm. After 1.5 revolutions, the tip is opposite its starting point, so displacement = 14 cm downward. Average speed = 21π/5400 ≈ 0.0122 cm s⁻¹, while averaRead more
The minute hand has radius 7 cm and moves for 90 minutes = 5400 s. It completes 1.5 revolutions. Therefore, distance = 1.5 × 2π × 7 = 21π cm ≈ 66 cm. After 1.5 revolutions, the tip is opposite its starting point, so displacement = 14 cm downward. Average speed = 21π/5400 ≈ 0.0122 cm s⁻¹, while average velocity = 14/5400 ≈ 0.0026 cm s⁻¹ downward.
For more NCERT Solutions of Class 9 Science Exploration Chapter 4 Describing Motion Around Us Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-4/
See lessWhy do suspended particles settle in muddy water over time but not in milk?
Suspended particles in muddy water are larger than the particles in a solution and remain undissolved. Due to their larger size, they settle at the bottom when the mixture is left undisturbed. Milk contains colloidal particles of moderate size, which remain uniformly dispersed throughout the liquid.Read more
Suspended particles in muddy water are larger than the particles in a solution and remain undissolved. Due to their larger size, they settle at the bottom when the mixture is left undisturbed. Milk contains colloidal particles of moderate size, which remain uniformly dispersed throughout the liquid. Therefore, unlike muddy water, milk does not show easy settling of its dispersed particles when left undisturbed with time.
For more NCERT Solutions of Class 9 Science Exploration Chapter 5 Exploring Mixtures and their Separation Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-5/
See lessHow is evaporation different from boiling?
Evaporation is a surface phenomenon in which liquid changes into vapour from its surface, usually below the boiling point. It is generally slow and can occur at different temperatures. Boiling occurs throughout the liquid at its boiling point and involves rapid vapour formation. Thus, evaporation isRead more
Evaporation is a surface phenomenon in which liquid changes into vapour from its surface, usually below the boiling point. It is generally slow and can occur at different temperatures. Boiling occurs throughout the liquid at its boiling point and involves rapid vapour formation. Thus, evaporation is a surface process, while boiling is a bulk process occurring at a specific temperature under given pressure only.
For more NCERT Solutions of Class 9 Science Exploration Chapter 5 Exploring Mixtures and their Separation Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-5/
See lessWhy do you see bright rays of sunlight when it passes through small gaps between the leaves of a dense tree?
Bright rays of sunlight become visible when sunlight passes through small gaps between leaves because dust and smoke particles in the air scatter the light. This scattering makes the path of the light beam visible. The scattering of light by particles is called the Tyndall effect. This effect can alRead more
Bright rays of sunlight become visible when sunlight passes through small gaps between leaves because dust and smoke particles in the air scatter the light. This scattering makes the path of the light beam visible. The scattering of light by particles is called the Tyndall effect. This effect can also be observed in dusty air and in floodlights at a sports stadium everywhere around us.
For more NCERT Solutions of Class 9 Science Exploration Chapter 5 Exploring Mixtures and their Separation Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-5/
See lessWhich of the following mixtures are correctly classified as homogeneous (Hm) and heterogeneous (Ht)? Choose the correct option. (i) Air — Hm, Milk — Ht, Sugar solution — Hm, Smoke — Hm (ii) Brass — Ht, Fog — Ht, Vinegar — Ht, Muddy water — Hm (iii) Copper sulfate solution — Hm, Salt solution — Hm, Milk — Hm, Bronze — Hm (iv) Muddy water — Ht, Milk — Ht, Blood — Ht, Brass — Hm
Option iv is correct. Muddy water, milk and blood are heterogeneous mixtures, whereas brass is a homogeneous mixture. A homogeneous mixture has a uniform composition throughout, while a heterogeneous mixture is not uniform. Thus, the classification in option iv agrees with the properties of these miRead more
Option iv is correct. Muddy water, milk and blood are heterogeneous mixtures, whereas brass is a homogeneous mixture. A homogeneous mixture has a uniform composition throughout, while a heterogeneous mixture is not uniform. Thus, the classification in option iv agrees with the properties of these mixtures described in the chapter, making it the correct option among the four choices given here in all parts equally.
For more NCERT Solutions of Class 9 Science Exploration Chapter 5 Exploring Mixtures and their Separation Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-5/
See less