The maximum efficiency of a lifting machine is

More Questions from Engineering Mechanics

• Principle of transmissibility of forces\n\nAccording to the principle of transmissibility, when a force acts upon a rigid body, its external effect (on overall equilibrium and motion) is:
• Converting rotational speed to angular velocity\n\nIf a body rotates at N revolutions per minute (rpm), what is its angular velocity ω in radians per second?
• Resultant of a force system\n\nThe process of determining a single force that can replace a given system of forces (i.e., the resultant) is called __________ of forces.
• Skidding on a level circular path\n\nA vehicle moves on a level circular track. Skidding can be avoided if the available frictional force between the tyres and the road is __________ the required centrifugal (outward) force for the turn.
• Type of motion: particle moving about a fixed axis\n\nThe motion of a particle moving around a fixed axis is best described as:
• Engineering mechanics – minimum external pull to initiate sliding on a rough horizontal plane\nA block of weight W rests on a rough, horizontal surface. The pull is applied at an angle θ to the horizontal. If θ equals the angle of friction, what is the minimum magnitude of force required to just start sliding the block?
• Simple harmonic motion (SHM) – relation between acceleration and displacement\nFor a particle executing SHM, the instantaneous acceleration a in terms of angular frequency ω and displacement y from the mean position is:
• Energy comparison – potential energy of a raised body vs. kinetic energy of a falling body\nFor the same mass and height reference, the potential energy of a vertically raised body is ______ the kinetic energy gained by a body after freely falling through that height (neglect air resistance).
• Triangle law of forces – equilibrium condition\nIf three concurrent forces are represented in magnitude and direction by the three sides of a triangle taken in order (head-to-tail), are the forces in equilibrium?
• Machines – reversibility and efficiency criterion\nA machine whose efficiency is less than 50% is termed as:

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