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Find the range of ball which, when projected with a velocity of 29.4 m s ^- 1 just passes over a pole 4.9 m high plz friends give me answer plz |
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Answer» :-Range of the BALL is 55 metres .Explanation :-We have :-→ Velocity of projection = 29.4 m/s→ Height of pole = 4.9 m________________________________From the FORMULA of maximum height of a projectile, we have :-H = u²sin²θ/2g⇒ 4.9 = [(29.4)² × sin²θ]/2(9.8)⇒ 4.9 = [864.36 × sin²θ]/19.6⇒ 864.36 × sin²θ = 19.6(4.9)⇒ sin²θ = 96.04/864.36⇒ sin²θ = 1/9⇒ sin θ = 1/3⇒ sin θ = 0.33We have sin θ = 1/3 , now solving for COS θ, we get :-⇒ cos θ = √8/3⇒ cos θ = 0.943________________________________Now from the formula of range of a projectile :-R = u²sin2θ/g⇒ R = u²(2sinθ)(cosθ)/g⇒ R = (29.4)²(2 × 0.33)(0.943)/9.8⇒ R = (864.36)(0.66)(0.943)/9.8⇒ R = 537.96/9.8⇒ R = 54.9 ≈ 55 m |
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