68 FALLING BODIES. 



14. A body falls freely for 6 seconds. What is the space trav- 

 ersed during the last 2 seconds of its fall ? 



15. A body is thrown directly upward with a velocity of 80.4 ft. 

 (a) What will be its velocity at the end of 3 seconds, and (&) in what 

 direction will it be moving? 



16. In Fig. 30, what is represented by the following lines : Fl ? 

 Fa? Aa? Fc? Dd? 



17. A body falls 357.28 ft. in 4 seconds. What was its initial 

 velocity ? 



18. A ball thrown downward with a velocity of 35 ft. per second 

 reaches the earth in 12 \ seconds, (a) How far has it moved, and 

 (&) what is its final veloc4ty ? 



19. (a) How long will a ball projected upward with a velocity of 

 3,216 ft. continue to rise ? (6) What will be its velocity at the 

 end of the fourth second ? (c) At the end of the seventh ? 



20. A ball is shot from a gun with a horizontal velocity of 1,000 

 feet, at such an angle that the highest point in its flight = 257.28 

 feet. What is its random? A us. 8000 ft. 



21. A body was projected vertically downward with a velocity of 

 10 feet ; it was 5 seconds falling. Required the entire space passed 

 over. Ans. 452ft. 



22. Required the final velocity of the same body. Ans. 170.8 ft. 



23. A body was 5 seconds rolling down an inclined plane and 

 passed over 7 feet during the first second, (a) Give the entire 

 space passed over, and (&) the final velocity. 



24. A body rolling down an inclined plane has at the end of the 

 first second a velocity of 20 feet ; (a) what space would it pass 

 over in 10 seconds? (&) If the height of the plane was 800 ft., 

 what was its length ? Last Ans. 1286.4 ft. 



25. A body was projected vertically upward and rose 1302.48 feet; 

 give (a) the time required for its ascent, (&) also the initial velocity. 



26. A body projected vertically downward has at the end of the 

 seventh second a velocity of 235.12 feet ; how many feet will it have 

 passed over during the first 4 seconds ? Ans. 297.28 ft. 



27. A body falls from a certain height ; 3 seconds after it has 

 started, another body falls from the height of 787.92 feet ; from 

 what height must the first fall if both are to reach the ground at 

 the same instant ? Ans. 1608 ft. 



Recapitulation. To be amplified by the pupil for 

 review. 



