Answer to Question #128969 in Chemistry for Alice

Question

(A) Safety regulations dictate that a ladder leaned against a building must be at an angle of 65°. A ladder that is 10.0 feet long will be used. How high up the side of building will the ladder safely reach? Include a diagram in your answer.

(B) A wind mill is 180 ft high. A guy wire will be fastened to the base of the windmill, 20 feet from the top and anchored into ground. The guy wire makes an angle of 40° with the ground. What length of the wire will be needed? Include a diagram in a diagram in your answer.

Answer 1

A)

$cos\beta=a/c$

$a = c ⋅ cos\beta$

$a = 10 ⋅ cos 65° = 4.23 feet$

B) a = 180 - 20 = 160 feet

$\alpha=40°$

$sin\alpha = a/c$

$c=a/sin\alpha$

$c=160/sin40° = 248.92 feet$