A boy is trying to catch adish sitting at height of 12 m from the surface of the water. A big fish is at a horizontal distance of 5m from him. What should be the length of his string to get the fish (a) 10 (b) 13 (c) 7 (d) 15
Answers
Answer:
Let AB be the height of the tip of the fishing rod from the water surface.
Let BC be the horizontal distance of the fly from the tip of the fishing rod.
Then, AC is the length of the string.
∴ AC
2
=AB
2
+BC
2
[ By Pythagoras theorem ]
∴ AC
2
=(1.8)
2
+(2.4)
2
∴ AC
2
=3.24+5.76
∴ AC
2
=9
∴ AC=3m
Thus, the length of the string out is 3m
She pulls the string at the rate of 5cm/s
∴ String pulled in 12 second = 12×5=60cm=0.6m
Let the fly be at point D after 12 seconds.
Length of string out after 12 second is AD.
⇒ AD = AC - String pulled by Nazima in 12 seconds.
⇒ AD=(3−0.6)m=2.4m
⇒ In △ADB,
AB
2
+BD
2
=AD
2
(1.8)
2
+BD
2
=(2.4)
2
BD
2
=5.76−3.24
BD
2
=2.52
∴ BD=1.587m
Horizontal distance of fly =BD+1.2m
Horizontal distance of fly =1.587m+1.2m
∴ Horizontal distance of fly =2.79m
Answer:
The correct answer is 13! Mark me as brainliest