(d) Here initial velocity of train u = 72km/h = 72 5/18 m s⁻¹, final velocity of train v = 0 and distance covered by train during this time s = 200 m ∴ v² - u² = 2as ∴ (0)² - (20)² = 2(a) × 200 or -400 = 400 a ⇒ a = - 1 m s⁻² Thus retardation of the train is 1 m s⁻². https://www.tiwariacademy.com/ncRead more
(d) Here initial velocity of train u = 72km/h = 72 5/18 m s⁻¹, final velocity of train v = 0 and distance covered by train during this time s = 200 m
∴ v² – u² = 2as
∴ (0)² – (20)² = 2(a) × 200 or -400 = 400 a ⇒ a = – 1 m s⁻²
Thus retardation of the train is 1 m s⁻².
The correct answer is:(c) both (a) and (b) A mixture can be made up of two or more elements (e.g., a mixture of oxygen and nitrogen gases) or two or more compounds (e.g., a mixture of water and alcohol). It can also contain both elements and compounds together. https://www.tiwariacademy.com/ncert-soRead more
The correct answer is:(c) both (a) and (b)
A mixture can be made up of two or more elements (e.g., a mixture of oxygen and nitrogen gases) or two or more compounds (e.g., a mixture of water and alcohol). It can also contain both elements and compounds together.
(a) Maximum in solids and minimum in gases. In solids, particles are tightly packed with strong intermolecular forces, keeping them in fixed positions. In gases, particles are far apart with very weak forces of attraction, allowing them to move freely. https://www.tiwariacademy.com/ncert-solutions/cRead more
(a) Maximum in solids and minimum in gases.
In solids, particles are tightly packed with strong intermolecular forces, keeping them in fixed positions.
In gases, particles are far apart with very weak forces of attraction, allowing them to move freely.
Ice – Homogeneous (solid form of water, same composition throughout). Air – Homogeneous (if pure and well-mixed, like clean air). (i) Ice and (iv) Air are homogeneous in nature. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/
Ice – Homogeneous (solid form of water, same composition throughout).
Air – Homogeneous (if pure and well-mixed, like clean air).
(i) Ice and (iv) Air are homogeneous in nature.
If a train travelling at 72 km h⁻¹ is brought to rest by applying brakes in a distance of 200 m, then the retardation of the train is
(d) Here initial velocity of train u = 72km/h = 72 5/18 m s⁻¹, final velocity of train v = 0 and distance covered by train during this time s = 200 m ∴ v² - u² = 2as ∴ (0)² - (20)² = 2(a) × 200 or -400 = 400 a ⇒ a = - 1 m s⁻² Thus retardation of the train is 1 m s⁻². https://www.tiwariacademy.com/ncRead more
(d) Here initial velocity of train u = 72km/h = 72 5/18 m s⁻¹, final velocity of train v = 0 and distance covered by train during this time s = 200 m
∴ v² – u² = 2as
∴ (0)² – (20)² = 2(a) × 200 or -400 = 400 a ⇒ a = – 1 m s⁻²
Thus retardation of the train is 1 m s⁻².
https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-7/
See lessA mixture is made up of (a) two or more elements. (b) two or more compounds. (c) both (a) and (b). (d) none of these.
The correct answer is:(c) both (a) and (b) A mixture can be made up of two or more elements (e.g., a mixture of oxygen and nitrogen gases) or two or more compounds (e.g., a mixture of water and alcohol). It can also contain both elements and compounds together. https://www.tiwariacademy.com/ncert-soRead more
The correct answer is:(c) both (a) and (b)
A mixture can be made up of two or more elements (e.g., a mixture of oxygen and nitrogen gases) or two or more compounds (e.g., a mixture of water and alcohol). It can also contain both elements and compounds together.
https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/
See lessThe time period of a vibrating object is 0.005 s. The frequency of waves emitted by it is
(c) ∴ Time period T = 0.005 s ∴ Frequency v = 1/T = 1/0.005 = 200 Hz https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/
(c) ∴ Time period T = 0.005 s
∴ Frequency v = 1/T = 1/0.005 = 200 Hz
https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/
See lessForces of attraction are (a) maximum in solids and minimum in gases. (b) maximum in gases and minimum in solids. (c) maximum in liquids and minimum in gases. (d) maximum in gases and minimum in liquids.
(a) Maximum in solids and minimum in gases. In solids, particles are tightly packed with strong intermolecular forces, keeping them in fixed positions. In gases, particles are far apart with very weak forces of attraction, allowing them to move freely. https://www.tiwariacademy.com/ncert-solutions/cRead more
(a) Maximum in solids and minimum in gases.
In solids, particles are tightly packed with strong intermolecular forces, keeping them in fixed positions.
In gases, particles are far apart with very weak forces of attraction, allowing them to move freely.
https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-1/
See lessWhich of the following are homogeneous in nature?
Ice – Homogeneous (solid form of water, same composition throughout). Air – Homogeneous (if pure and well-mixed, like clean air). (i) Ice and (iv) Air are homogeneous in nature. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/
Ice – Homogeneous (solid form of water, same composition throughout).
Air – Homogeneous (if pure and well-mixed, like clean air).
(i) Ice and (iv) Air are homogeneous in nature.
https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/
See less