Question

A ladder of length 3m weighs 200N and has its centre of gravity 120cm from its bottom. A 50N weight is attached to its top. Calculate the amount of work required to raise the ladder from a
horizontal position on the ground to a vertical position. (a) 390J (b) 240J (c) 150J (d) 750J

Answer 1

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To raise it from horizontal to vertical, you are raising the center of gravity by 1.2m (Its distance from bottom ).

work done = 200 * 1.2 = 240J

To raise the weight to a height 3m

50 * 3 = 150J

Total work = 240 + 150 = 390J❤️

Answer 2

Answer:

a

Explanation: