Physics 11 Film Science
Questions for: Extreme Machines: Earth Breakers

Background: mining - it's simple: no friction, no force and then no ore gets removed.

1. The TBM's most recent major "underwater" assignment was what?

2. How had Napoleon planned to use a tunnel under the English Channel?

3. The TBM's cutter head teeth grinding into the rock ahead are made of what substance?

4. The energy from what tunnelling "machines" were used to construct the 41 mile long Old Croton Aqueduct running under 5^th Avenue New York City?

5. What would happen to the TBM's body if it were not held in place when the rotating boring head is pushed against fresh rock?

6. How are the enormously powerful TBM's kept on the correct path during their tunnelling assignments?

7. a) If the Long Wall Shearer applies a 2 000 N force to its 3 000 N boom, what is its acceleration?

b) After 10 s, the boom would be swinging how fast?

8. How does the Joy Continuous Miner cutter head design compare with the cutter head on the TBM?

9. A pit pony would need what force to drag a 15 kg wagon carrying 65 kg of rock along a section of mine floor where the µ is 0.8?

10. During the 1944 "Great Escape" from Stalag Luft III through a tunnel, a British airman pushes with 800 N against the mini trolley carrying another Allied POW. The person on the trolley is 70 kg and the µ is 0.2. Find: the force to overcome friction, the excess force from the airman's push, and trolley's acceleration due to the excess force.

11. a) How were the networks of tunnels dug in the southern regions of Vietnam?

b) A 120 N push would move a food box of what weight along a section of mud floor if the µ is 1.2?

12. How does the Cactus Crane operating in the South African Western Deep Levels gold mine apply its force?

13. In a coal mine, the Stoke Jumbo drills holes for what purpose?

14. a) A Load Haul Dumper exerts a 39 000 N force against its bucket scraping along the mine floor. If the µ is 1.4, what total weight can be moved?

b) If the bucket has a mass of 2 000 kg, what weight of coal can be moved? (Hint: total - bucket)

15. A Walking Drag Line pulls with 90 000 N on its 5 000 kg bucket. What weight of rock could be dragged if the µ is 1.2? (Hint: total - bucket)