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Practice
practice problem 1
Can this be made into some kind of problem?
Eight parachutists are to attempt a unique, low-altitude descent in September. They will leap from an altitude of just 75 m — lower than Big Ben but higher than Nelson's Column …. From exit to full inflation takes around 4 seconds …. That will leave around 30 m of descent with a full canopy in the 75 m drop. The previous lowest jump using military parachutes was from around 130 m, when US troops invaded the Caribbean island of Grenada in 1983.
(Coghlan, Andy. "For the Low Jump." New Scientist. 26 July 1997: 21)
solution
- Answer it.
practice problem 2
A problem for Americans only. Verify the often stated rule of thumb that one newton is approximately equal to a quarter pound.
solution
Well, here ya go …
| F = | ma |
| 2.2 lb = | (1 kg)(9.8 m/s2) |
| 1 lb = | 4.45 N |
| ⅕ < 1 N < ¼ lb | |
Not quite a quarter pound, but you get the idea.
practice problem 3
Write something different.
solution
- Answer it.
practice problem 4
Write something completely different.
solution
- Answer it.