1. Inertia is the measure of the mass of the body. The greater is the mass of the body; the greater is its inertia and vice-versa. (a) Mass of a stone is more than the mass of a rubber ball for the same size. Hence, inertia of the stone is greater than that of a rubber ball. (b) Mass of a train is moreRead more

    Inertia is the measure of the mass of the body. The greater is the mass of the body; the greater is its inertia and vice-versa.
    (a) Mass of a stone is more than the mass of a rubber ball for the same size. Hence, inertia of the stone is greater than that of a rubber ball.
    (b) Mass of a train is more than the mass of a bicycle. Hence, inertia of the train is greater than that of the bicycle.
    (c) Mass of a five rupee coin is more than that of a one-rupee coin. Hence, inertia of the five rupee coin is greater than that of the one-rupee coin.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    See less
    • 0
  2. Here, r = 42250 km = 42250000 m T = 24 h = 24 × 60 × 60 s Using Speed, v = 2πr ÷ T v = (2 × 3.14 × 42250000) ÷ (24 × 60 × 60) m/s = 3070.9 m/s = 3.07 km/s For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    Here,
    r = 42250 km = 42250000 m
    T = 24 h = 24 × 60 × 60 s
    Using Speed, v = 2πr ÷ T
    v = (2 × 3.14 × 42250000) ÷ (24 × 60 × 60) m/s
    = 3070.9 m/s = 3.07 km/s

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    See less
    • 1
  3. (a) Yes, a body can have acceleration even when its velocity is zero. When a body is thrown up, at highest point its velocity is zero but it has acceleration equal to acceleration due to gravity. (b) Yes, an acceleration moving horizontally is acted upon by acceleration due to gravity that acts vertRead more

    (a) Yes, a body can have acceleration even when its velocity is zero. When a body is thrown up, at highest point its velocity is zero but it has acceleration equal to acceleration due to gravity.
    (b) Yes, an acceleration moving horizontally is acted upon by acceleration due to gravity that acts vertically downwards.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    See less
    • 0
  4. Here, u = 0 m/s, s = 20 m, a = 10 ms⁻², v = ?, t = ? Using v² – u² = 2as We have, v² – 0² = 2 × 10 × 20 = 400 ⇒ v = 20 ms⁻¹. and t = (v – u) ÷ a = 20 ÷ 10 = 2 s. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    Here, u = 0 m/s, s = 20 m, a = 10 ms⁻², v = ?, t = ?
    Using v² – u² = 2as
    We have, v² – 0² = 2 × 10 × 20 = 400 ⇒ v = 20 ms⁻¹.
    and t = (v – u) ÷ a = 20 ÷ 10 = 2 s.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    See less
    • 0
  5. Here, u = 0 m/s a = 3 ms⁻² t = 8 s Using, s = ut + ½ at² s = 0 × 8 + ½ × 3 × 8² = 96 m. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    Here, u = 0 m/s
    a = 3 ms⁻²
    t = 8 s
    Using, s = ut + ½ at²
    s = 0 × 8 + ½ × 3 × 8² = 96 m.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-8/

    See less
    • 0