(1)如图所示,a是
(2)为确保安全,应考虑钢绳的承受力。若夯机使用了质量为4×104千克的夯锤,则钢绳能承受的拉力至少多大?(不计滑轮、钢绳自重及摩擦)
(3)夯实地基所需能量来自于夯锤的重力势能。若质量为4×104千克的夯锤,从10米高处下落至地面,重力做了多少功?
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2