1. Given m = mass of bullet = 50 gm = 0.50 kg M = mass of tiger = 60 kg v = Velocity of bullet = 150 m/s V = Velocity of tiger = – 10m/s (∴ It is coming from opposite direction n = no. of bullets fired per second at the tiger so as to stop it.) Pi = 0, before firing ...(i) Pf = n(mv) + MV ...(ii) ∴ FroRead more

    Given m = mass of bullet = 50 gm = 0.50 kg
    M = mass of tiger = 60 kg
    v = Velocity of bullet = 150 m/s
    V = Velocity of tiger = – 10m/s
    (∴ It is coming from opposite direction n = no. of bullets fired per second
    at the tiger so as to stop it.)
    Pi = 0, before firing …(i)
    Pf = n(mv) + MV …(ii)
    ∴ From the law of conservation of momentum,
    Pi = Pf
    ⇒ 0 = n(mv) + MV
    ⇒ n = MV/mv
    = -60/(-10)/0.05×150 = 80.

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    • 8
  2. (a) Force on the floor of the helicopter by the crew and passengers = apparent weight of crew and passengers = 500 (10 + 15) = 12500 N (b) Action of rotor of helicopter on surrounding air is Obviously vertically downwards, because helicopter rises on account of reaction of this force. Thus force ofRead more

    (a) Force on the floor of the helicopter by the crew and passengers
    = apparent weight of crew and passengers
    = 500 (10 + 15)
    = 12500 N
    (b) Action of rotor of helicopter on surrounding air is Obviously vertically
    downwards, because helicopter rises on account of reaction of this
    force. Thus force of action
    = (2000 + 500) (10 + 15)
    = 2500 × 25
    = 62,500 N
    (c) Force on the helicopter due to surrounding air is obviously a reaction.
    As action and reaction are equal and opposite, therefore
    Force of reaction F´ = 62,500 vertically upwards.

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    • 7
  3. Suppose, a = acceleration produced if m₁ and m₂ are tied together, F = 100 N Let a₁ and a₂ be the acceleration produced in m₁ and m₂, respectively. a₁ = 10 ms⁻², a₂ = 20 ms⁻² (given) Again m₁ = F/a₁ and m₂ = F/ a₂ m₁ = 100/10 = 10 ms⁻² and m₂ = 100/20 = 5 ms⁻² m₁ + m₂ = 10 + 5 = 15 So, a = F/m₁ + m₂Read more

    Suppose, a = acceleration produced if m₁ and m₂ are tied together,
    F = 100 N
    Let a₁ and a₂ be the acceleration produced in m₁ and m₂, respectively.
    a₁ = 10 ms⁻², a₂ = 20 ms⁻² (given)
    Again m₁ = F/a₁ and m₂ = F/ a₂
    m₁ = 100/10 = 10 ms⁻²
    and m₂ = 100/20 = 5 ms⁻²
    m₁ + m₂ = 10 + 5 = 15
    So, a = F/m₁ + m₂ = 100/15 = 20/3
    = 6.67 ms⁻²

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    • 8
  4. Force of friction = 0·5 N per quintal f = 0·5 × 2000 = 1000 N m = 2000 quintals = 2000 × 100 kg sin θ = 1/50, a= 2m/s² In moving up an inclined plane, force required against gravity = mg sin θ = 39200 N And force required to produce acceleration = ma = 2000 × 100 × 2 = 40,0000 N Total force requiredRead more

    Force of friction = 0·5 N per quintal
    f = 0·5 × 2000 = 1000 N
    m = 2000 quintals = 2000 × 100 kg
    sin θ = 1/50, a= 2m/s²
    In moving up an inclined plane, force required against gravity
    = mg sin θ = 39200 N
    And force required to produce acceleration = ma
    = 2000 × 100 × 2 = 40,0000 N
    Total force required = 1000 + 39,200 + 40,0000
    = 440200 N.

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    • 7
  5. F = 98 N, R = 45 × 9·8 = 441 N μ² = F'/R = 0.22 Angle of friction θ = tan⁻¹ μ = tan⁻¹ 0·22 = 12°24′

    F = 98 N, R = 45 × 9·8 = 441 N
    μ² = F’/R = 0.22
    Angle of friction θ = tan⁻¹ μ = tan⁻¹ 0·22 = 12°24′

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    • 6