A bird is sitting on the top of a tree which is 80 m high. The angle o...
Hi guys
draw the diagram.. here are the steps...
triangle ACB
tan 45 degree = 80/y
1= 80/y
y=80m ---------(1)
triangle DEB
tan 30 degree = 80/x
1/ root 3= 80/x
x= 80 root3 --------(2)
from 1 and 2 we get
80root3 - 80
80(root3-1)m
speed of the bird= 2 sec
80(root3-1)/2
2 and 80 we get cancelled that will give us 40
40(root3-1)
SORRY I KNOW TILL THIS MUCH CAN SOMEONE PLZ TILL ME THE NEXT STEP
40(root3-1)*60 * 60/1000
cancell the zeroes
144(root3-1)
IF THERE IS ANY MISTAKE PLZ LET ME KNOW....
A bird is sitting on the top of a tree which is 80 m high. The angle o...
**Solution:**
Let's break down the problem step by step:
1. **Identify the given information**:
- Height of the tree (h) = 80 m
- Initial angle of elevation (θ1) = 45 degrees
- Final angle of elevation (θ2) = 30 degrees
- Time taken (t) = 2 seconds
2. **Draw a diagram**:
- Draw a triangle ABC, where A represents the point of observation on the ground, B represents the initial position of the bird, and C represents the final position of the bird after 2 seconds.
- AB represents the height of the tree, BC represents the horizontal distance covered by the bird, and AC represents the length of the bird's flight path.
3. **Find the distance covered by the bird horizontally (BC)**:
- Since the bird flies horizontally, BC remains constant.
- We can use the formula: BC = v*t, where v is the speed of the bird and t is the time taken.
- Substitute the given values: BC = v * 2
4. **Find the height of the bird at the final position (h2)**:
- In triangle ABC, tan(θ1) = AB/BC (using the initial angle of elevation)
- Substitute the values: tan(45) = 80/BC
- Rearrange the equation to solve for BC: BC = 80/tan(45)
5. **Substitute the value of BC in terms of v into the equation from step 3**:
- BC = v * 2
- Substitute the value of BC from step 4: 80/tan(45) = v * 2
- Simplify the equation: 80√2 = 2v
- Divide both sides by 2: v = 40√2
6. **Calculate the speed of the flying bird**:
- Use a calculator to find the approximate value of v: v ≈ 56.57 m/s
7. **Final Answer**:
- The speed of the flying bird is approximately 56.57 m/s.
To make sure you are not studying endlessly, EduRev has designed Class 10 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 10.