作业帮A uniform ladder 7.10m long weighing 500N rests with one end on the ground and the other end against a perfectly smooth vertical wall.The ladder rises at 55.0∘ above the horizontal floor.A 800N painter finds that she can climb 2.95m up the ladd
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A uniform ladder 7.10m long weighing 500N rests with one end on the ground and the other end against a perfectly smooth vertical wall.The ladder rises at 55.0∘ above the horizontal floor.A 800N painter finds that she can climb 2.95m up the ladd
A uniform ladder 7.10m long weighing 500N rests with one end on the ground and the other end against a perfectly smooth vertical wall.The ladder rises at 55.0∘ above the horizontal floor.A 800N painter finds that she can climb 2.95m up the ladder,measured along its length,before it begins to slip.
What force does the wall exert on the ladder?
Find the friction force that the floor exerts on the ladder
Find the normal force that the floor exerts on the ladder.
A uniform ladder 7.10m long weighing 500N rests with one end on the ground and the other end against a perfectly smooth vertical wall.The ladder rises at 55.0∘ above the horizontal floor.A 800N painter finds that she can climb 2.95m up the ladd
Sol:
sin(55°) = 0.82;
cos(55°) = 0.57
(1) the force which the wall exert on the ladder is only the normal force.
(2) by the force balance equation.
N = G1 + G2 = 1300N,
by the moment balance equation.
NL = fl + G1l1 + G2l2
where,
L = 7.10m× 0.57 = 4.047m,
l = 7.10m × 0.82 = 5.822m,
l1 = 7.10 ÷ 2 × 0.57 = 2.024m,
l2 = (7.10 - 2.95)m × 0.57 = 2.366m
we'll get
f = 408.85N
1，D（问你当使用后面的公式计算加速度时，下面那个公式是正确的）
2，C（下图说的是一辆农民的卡车的运动，问你总位移，假设向北是正方向，即向上）
3，D（问你如何计算变加速度运动的物体的瞬时加速度）（A是计算位移时间曲线的斜率，B是计算位移时间曲线的面积，C是计算速度时间曲线的面积，D是计算速度时间曲线的斜率）
翻译的可能不太好，但意思是对的
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1，D（问你当使用后面的公式计算加速度时，下面那个公式是正确的）
2，C（下图说的是一辆农民的卡车的运动，问你总位移，假设向北是正方向，即向上）
3，D（问你如何计算变加速度运动的物体的瞬时加速度）（A是计算位移时间曲线的斜率，B是计算位移时间曲线的面积，C是计算速度时间曲线的面积，D是计算速度时间曲线的斜率）
翻译的可能不太好，但意思是对的
希望帮助到您
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