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A ladder 10 m long,leans against a vertical wall at an angle of 70° to the ground.if the ladder slips down the wall 4m,find,correct to 2 significant figure

(a) the new angle which the ladder makes with the ground

(b) the distance the ladder slipped back on the ground from it's original position


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Answer:

(a) The new angle the ladder makes with the ground = 32.66°

(b) The distance the ladder slipped back on the ground from it's original position = 5 m

Explanation:

The given parameters are;

The length of the ladder = 10 m

Angle of inclination of the ladder = 70°

Length to which the ladder slips down the wall = 4 m

(a) The height of the wall adjacent to the ladder = 10×sin(70°) ≈ 9.4 m

The new height of the wall adjacent to the ladder after the ladder slips down 4 m = 9.4 - 4 = 5.4 m

Therefore, the new angle of inclination of the ladder = sin⁻¹(5.4/10) = 32.66°

The new angle the ladder makes with the ground = 32.66°

(b) The distance the ladder slipped back on the ground from its original position is found as follows

The initial distance of the base of the ladder from the wall = 10 × cos(70°) = 3.42 m

The distance of the base of the ladder from the wall after slipping 4 m down the wall = 10 × cos(32.66°) ≈ 8.42 m.

Therefore, the amount by which the ladder slip back on the ground from its original position = 8.42 - 3.42 = 5 m.

The distance the ladder slipped back on the ground from it's original position = 5 m.

User Cynthia Simiyu
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