Calendar: 1866-1867 Page 477

APPLIED SCIENCES 479 Find the relation between the power and weight on the screw when the thread is rough Ex If the thread makes 50 turns in inches and the power acts at an arm of feet the limiting angle of friction being sin- find the mechanical advantage number of equal weights are suspended at equal distances on weightless cord draw diagram of forces for it and show that the tangents of the inclinations of the successive parts of the cord are in Arithmetical Progression Hence show that in heavy uniform rope the tangent of the inclination at any point is the weight of the portion of the rope between that point and the lowest point divided by the tension at the lowest point In roof of which the span is 48 feet the height 10 feet and the weight of roofing lb per square foot the rafters are feet apart and are divided into equal parts the tie-beam is bisected and also divided into three equal parts and the points of division are joined as in the accompanying figure find by the method of sections or otherwise the stresses along the several pieces mass of earth is just prevented from slipping by wall which reaches to level with the top of it along what section is there the greatest tendency to slip Hence find the force neces- sary to support it Define the line of resistance in structure wall of which the section is right-angled triangle and of which the base is two-thirds of the height the specific gravity of the mate- rial being sustains the pressure of water on its vertical face find the equation to the line of resistance also its distance from the outer edge of the wall at depth of 12 feet What must be the ratio of the base to the height when the wall is on the point of being overturned What is the energy of moving body Find the loss of energy arising from the impact of two inelastic balls of given weight moving with given velocities How do you account for this loss If the weights of the bodies are and lbs and their velo-