INSTRUCTIONS: GIVE LENGTHS TO THREE SIGNIFICANT DIGITS AND ANGLE MEASURES TO THE NEAREST TENTH OF A DEGREE.
1. What is the angle of elevation of the sun when tree 6.25m tall casts a shadow 10.1m long?
2. A boy flying a kite is standing 30 ft. from a point directly under the kite. If the string to the kite is 50 ft. long, find the angle of elevation of the kite.
3. A cable 4 m long is attached to a pole. The cable is staked to the ground 1.75m from the base of the pole. Find the angle of elevation.
4. How far from the base of building is the bottom of a 30 ft ladder that makes an angle of 75º with the ground.
2006-11-14 11:47:21 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Follow ditz's advice (make a diagram) as you read these directions for solving the 4 problems:
1. assuming that the sun is a point source and the earth's surface is flat:
angle = arctan (6.25/10.1)
2. assuming that the string forms a straight line, and that the end of the string is on the ground:
sqrt(50^2 - 30^2)
3. arccos (1.75/4)
4. 30 cos (75 degrees)
2006-11-14 12:09:14 · answer #1 · answered by actuator 5 · 0⤊ 0⤋
1. The angle of elevation is 31.8°. I got this by taking the two lengths given, squaring them both, and adding them together. Taking the sqare root of that number to give me 11.877 meters. I then took 6.25 / 11.877 to find the sine of the angle of elevation.
2. The angle of elevation 53.1°. I got this by taking the hypotenuse (50) squared, subtracting 30 squared, and taking the square root of that answer (which came out to be 40). The I took 40 / 50 to get 0.8 as the sine of the angle of elevation.
3. The angle of elevation is 64.2°. I found this answer is worked out very similar to the last answer (number 2).
4. The base of the building is 7.764 feet away from the base of the ladder. I found this by finding the sine of 75° and then multiplying it by 30 to give me the height of the building (28.978). Then I took 30 squared, subtracted 28.978 squared, and taking the square root of the answer.
I hope this helps you to understand these problems.
2006-11-14 12:15:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋
I'd seriously help you cuz I'm good at that stuff, but I don't have paper with me so. . . sucks to be you
2006-11-14 11:48:56 · answer #3 · answered by Anonymous · 0⤊ 1⤋
draw pictures. they should make triangles. it should clear it up
2006-11-14 11:49:49 · answer #4 · answered by Ambino 4 · 0⤊ 1⤋