Lesson 3

Self-Check 2

1. An airplane being flown at a vertical height of 100 m is approaching the runway of the local airport. From the cockpit, the angle of depression to the start of the runway is 5°. To the nearest 10 m, calculate the horizontal distance between the plane and the start of the runway. Answer

2. A 16-ft ladder rests against a building and makes an angle of 76° with the ground. How far is the foot of the ladder from the wall? Round your answer to one decimal place. Answer

3. At noon in Whitehorse on June 21, a 5-m flagpole cast a 3.5-m shadow. To the nearest degree, what was the angle of elevation of the Sun? Answer

4. A loading ramp makes an angle of 20° with the ground. One end of the ramp rests on the ground. The other end leans against a storage platform that is 1 m high. How long is the ramp? Round your answer to one-tenth of a metre. Answer

5. Think back to the Kicking Horse Pass from the previous example. The Big Hill line had to be replaced. By 1909 the CPR, using a design from engineer John Schwitzer, completed a pair of spiral tunnels that reduced the grade to 2.2%. Each spiral tunnel makes a three-quarter turn. The lower tunnel was constructed under Mt. Ogden, and the upper tunnel was made under Cathedral Mountain.
   
   
   
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   The upper tunnel under Cathedral Mountain is inclined at 0.983° to the horizontal. The change in elevation is 17 m. To the nearest metre, what is the length of this tunnel? Answer

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