108 THE INCLINED PLANE. 



11. With a fixed pulley, what power will support a weight of 50 

 pounds ? 



12. With a movable pulley, what power will support a weight of 

 50 pounds 'I 



13. What is the greatest effect of a system of 3 movable and 4 

 fixed pulleys, the power applied being 75 pounds ? 



14. With a system of 5 movable pulleys, one end of the rope 

 being attached to the fixed block, what power will raise a ton ? |/fc 



15. If in the system mentioned in the problem above, the rope be 

 attached to the movable block, what power will raise a ton ? 



16. With a pulley of 6 sheaves in each block, what is the least 

 power that will support a weight of 1,800 pounds, allowing ^"for 

 friction ? What will be the relative velocities of P and W ? 



17. Figure a set of pulleys by which a power of 50 pounds will 

 support a weight of 250 pounds. 



18. The height of an inclined plane is one-fifth its horizontal 

 base. A globe weighing 250 Kg. is supported in place by a force 

 acting at an angle of 45 with the base. The pressure of the globe 

 upon the plane is less than 250 Kg. By construction and measure- 

 ment, determine the intensity of the supporting force. 



19. With the conditions as given in the last problem, except that 

 the pressure of the globe upon the plane is more than 250 Kg., de- 

 termine the intensity of the supporting force. 



20. The base of an inclined plane is 10 feet ; the height is 3 feet. 

 What force, acting parallel to the base, will balance a weight of 

 2 tons'? 



21. An incline has its base 10 feet ; its height, 4 feet : how heavy a 

 ball will 50 pounds power roll up f 



22. How great a power will be required to support a ball weighing 

 40 pounds on an inclined plane whose length is 8 times its height ? 



23. A weight of 800 pounds rests upon an inclined plane 8 feet 

 high, being held in equilibrium by a force of 25 pounds acting 

 parallel to the base. Find the length of the plane. 



24. A load of 2 tons is to be lifted along an incline. The power 

 is 75 pounds ; give the ratio of the incline which may be used. 



25. A 1500 pound safe is to be raised 5 feet. The greatest power 

 that can be applied is 250 pounds. Give the dimensions of the 

 shortest inclined plane that can be used for that purpose. 



Recapitulation. To be amplified by the pupil for 

 review. 



