Question 290 Deck General

The correct answer is A) The thrust on the boom is greater at 60°. When the boom is at a 60° angle to the horizontal, the thrust or force acting on the boom is greater compared to when the boom is at a 20° angle. This is because the vertical component of the load's weight increases as the boom angle increases, leading to higher stresses on the boom structure. The other answer choices are incorrect because the stress on the heel block, head block, and topping lift are not necessarily dependent on the boom angle in the way described.