1. When the bus accelerates and moves forward, it acquires a state of motion. However, the luggage kept on the roof, owing to its inertia, tends to remain in its state of rest. Hence, with the forward movement of the bus, the luggage tends to remain at its original position and ultimately falls from thRead more

    When the bus accelerates and moves forward, it acquires a state of motion.
    However, the luggage kept on the roof, owing to its inertia, tends to remain in its
    state of rest. Hence, with the forward movement of the bus, the luggage tends to
    remain at its original position and ultimately falls from the roof of the bus. To
    avoid this, it is advised to tie any luggage kept on the roof of a bus with a rope.

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

    See less
    • 0
  2. Inertia of an object tends to resist any change in its state of rest or state of motion. When a carpet is beaten with a stick, then the carpet comes to motion. But, the dust particles try to resist their state of rest. According to Newton's first law of motion, the dust particles stay in a state ofRead more

    Inertia of an object tends to resist any change in its state of rest or state of motion.
    When a carpet is beaten with a stick, then the carpet comes to motion. But, the
    dust particles try to resist their state of rest. According to Newton’s first law of
    motion, the dust particles stay in a state of rest, while the carpet moves. Hence,
    the dust particles come out of the carpet.

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

    See less
    • 0
  3. Yes. Even when an object experiences a net zero external unbalanced force, it is possible that the object is travelling with a non-zero velocity. This is possible only when the object has been moving with a constant velocity in a particular direction. Then, there is no net unbalanced force applied oRead more

    Yes. Even when an object experiences a net zero external unbalanced force, it is
    possible that the object is travelling with a non-zero velocity. This is possible only
    when the object has been moving with a constant velocity in a particular direction.
    Then, there is no net unbalanced force applied on the body. The object will keep
    moving with a non-zero velocity. To change the state of motion, a net non-zero
    external unbalanced force must be applied on the object.

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

    See less
    • 0
  4. Mass of one of the objects, m₁ = 100 g = 0.1 kg Mass of the other object, m₂ = 200 g = 0.2 kg Velocity of m1 before collision, v₁ = 2 m/s Velocity of m2 before collision, v₂ = 1 m/s Velocity of m1 after collision, v₄ = 1.67 m/s Velocity of m2 after collision = v₄ According to the law of conservationRead more

    Mass of one of the objects, m₁ = 100 g = 0.1 kg
    Mass of the other object, m₂ = 200 g = 0.2 kg Velocity of m1 before collision, v₁ = 2 m/s
    Velocity of m2 before collision, v₂ = 1 m/s
    Velocity of m1 after collision, v₄ = 1.67 m/s
    Velocity of m2 after collision = v₄
    According to the law of conservation of momentum:
    Total momentum before collision = Total momentum after collision
    m₁v₁ + m₂v₂ = m₁v₃ + m₂v₄
    ⇒ 0.1×2 + 0.2×1 = 0.1×1.67 + 0.2×v₄
    ⇒ 0.4 = 0.67 + 0.2×v₄
    ⇒ v₄ = 1.165 m/s
    Hence, the velocity of the second object becomes 1.165 m/s after the collision.

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

    See less
    • 0
  5. Mass of the rifle, m1 = 4 kg Mass of the bullet, m2 = 50g = 0.05 kg Recoil velocity of the rifle = v₁ Bullet is fired with an initial velocity, v₂ = 35 m/s Initially, the rifle is at rest. Thus, its initial velocity, v = 0 Total initial momentum of the rifle and bullet system = (m1 + m2) v = 0 TotalRead more

    Mass of the rifle, m1 = 4 kg
    Mass of the bullet, m2 = 50g = 0.05 kg
    Recoil velocity of the rifle = v₁
    Bullet is fired with an initial velocity, v₂ = 35 m/s
    Initially, the rifle is at rest.
    Thus, its initial velocity, v = 0
    Total initial momentum of the rifle and bullet system = (m1 + m2) v = 0
    Total momentum of the rifle and bullet system after firing:
    = m₁ v₁ + m2v2 = 4(v1) + 0.05×35 = 4v1 + 1.75
    According to the law of conservation of momentum:
    Total momentum after the firing = Total momentum before the firing
    4 v₁ + 1.75 = 0
    ⇒ v₁ = – 1.75/4 = – 0.4375 m/s
    The negative sign indicates that the rifle recoils backwards with a velocity of 0.4375 m/s.

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

    See less
    • 0