SafetyCâu 97 / 110
A plumber sets an extension ladder to reach a roof vent terminal. Using the 4-to-1 rule, how far should the base be from the wall if the ladder contacts the wall 16 ft up?
a.4 ft
b.2 ft
c.8 ft
d.16 ft
Giải thích
The 4-to-1 rule places the base 1 ft out for every 4 ft of working height, so 16 / 4 = 4 ft from the wall. This angle keeps the ladder from sliding out at the base or tipping back. The ladder should also extend at least 3 ft above the roof edge for a safe transition.
Trích dẫn luật: 29 CFR 1926.1053Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
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