<\/strong><\/p>\nQuestion 6. \nA 1.5 m tall boy is standing at some distance from a 30 m tall building. The angle of elevation from his eyes to the top of the building increases from 30\u00b0 to 60\u00b0 as he walks towards the building. Find the distance he walked towards the building. \nSolution: \nIn this fig, AB is height of the building and CD is the height of the boy. Angle of elevation from boy’s eyes to the top of the building is 30\u00b0 and after y m walk’s towards building the angle of elevation becomes 60\u00b0. \n <\/p>\n
Question 7. \nFrom a point on the ground, the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20 m high building are 45\u00b0 and 60\u00b0 respectively. Find the height of the tower. \nSolution: \nIn this fig. AB is height of tower which is kept on the to a 20m high tower BC Angle of elevation of the top and bottom of tower from a 1 point D on ground is 60\u00b0 and 45\u00b0 repectivelv. \n \nHence, the height of the tower is 20(\\(\\sqrt{3}\\) – 1) m.<\/p>\n
Question 8. \nA statue, 1.6 m tall, stands on the top of a pedestal. From a point on the ground, the angle of elevation of the top of the statue is 60\u00b0 and from the same point the angle of elevation of the top of the pedestal is 45\u00b0. Find the height of the pedestal. \nSolution: \nIn this fig. AB is the height of the statue and BC is the height of pedestal. At the poind D on the ground the angle of elevation of the top of the statue and top of pedestal is 60\u00b0 and 45\u00b0 respectively. \n \nTherefore, the height of pedestal is BC = 2.19 m (approx)<\/p>\n
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Question 9. \nThe angle of elevation of the top of a building from the foot of a tower is 30\u00b0 and the angle of elevation of the top of the tower from the foot of the building is 60\u00b0. If the tower is 50 m high, find the height of the building. \nSolution: \nIn this fig, ABC is the height of tower and CD is the height of building. Angle of elevation of the top of the building from the foot of a tower is 30\u00b0 and the angle of elevation of the top of the tower from the foot of a building is 60\u00b0. \n <\/p>\n
Question 10. \nTwo poles of equal heights are standing opposite each other on either side of the road, which is 80 m wide. From a point between them on the road, the angles of elevation of the top of the poles are 60\u00b0 and 30\u00b0 respectively. Find the height of the poles and the distance of the point from the poles. \nSolution: \nIn this fig, AB and CD are poles of equal height on either side of 80 m wide road. There is a point P on the road in which the angle of elevation of the poles are 60\u00b0 and 30\u00b0 respectively. \nLet the distance between the point P and the first pole is x m \n\u2234 The distance between the point P and the second pole is 80 – x m \n \nTherefore, height of each poles is 20\\(\\sqrt{3}\\) m and distance of the point from first pole is x = 20m and (80 – x) = (80 – 20) = 60m<\/p>\n
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Question 11. \nA TV tower stands vertically on a bank of a canal. From a point on the other bank directly opposite the tower, the angle of elevation of the top of the tower is 60\u00b0. From another point 20 m away from this point on the line joining this point to the foot of the tower, the angle of elevation of the top of the tower is 30\u00b0 (see the given figure). Find the height of the tower and the width of the CD and 20 m from pole AB. \n \nSolution: \nIn this fig, AB is the height of the cable tower and CD is the height of the building. The angle of elevation of the top of a cable tower from the top of the building is 60\u00b0 and angle of depression of the foot of a cable tower from the top of the building is 45\u00b0 \nIn \u2206ABC, \n \nSo, height of the three = AB = 10\\(\\sqrt{3}\\) m and width of the river = BC = 10m<\/p>\n
Question 12. \nFrom the top of a 7 m high building, the angle of elevation of the top of a cable tower is 60\u00b0 and the angle of depression of its foot is 45\u00b0. Determine the height of the tower. \nSolution: \nIn this fig. AB is the height of the cable towar and CD is the height of the building. The angle of elevation of the top of a cable towar from the top of the building is 60 and the angle of depression of the foot of a cable tower from the top of tire building is 45\u00b0. \n \nTherefore, height of the tower AB = AE + EB = 7\\(\\sqrt{3}\\) + 7 = 7(\\(\\sqrt{3}\\) + 1)<\/p>\n
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Question 13. \nAs observed from the top of a 75 m high lighthouse from the sea-level, the angles of depression of two ships are 30\u00b0 and 45\u00b0. If one ship is exactly behind the other on the same side of the lighthouse, find the distance between the two ships. \nSolution: \nIn this fig, AB is the height of the lighthouse and at point C and D there are two ships just behind each other. Angle of depression from the top of the lighthouse to the ships are 30\u00b0 and 45\u00b0 respectively. \n \nTherefore, the distance between the two ships are \nCD = BD – BC \n <\/p>\n
Question 14. \nA 1.2 m tall girl spots a balloon moving with the wind in a horizontal line at a height of 88.2 m from the ground. The angle of elevation of the balloon from the eyes of the girl at any instant is 60\u00b0. After sometime, the angle of elevation reduces to 30\u00b0 (see figure). Find the distance travelled by the balloon during the interval. \nSolution: \nInitial height = 88.2 – height of the girl \n= 88.2 – 1.2 = 87 m \n \nTherefore, the distance travelled by the ballon during the interval CQ \\(\\frac{296 \\sqrt{3}}{5}\\) m.<\/p>\n
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Question 15. \nA straight highway leads to the foot of a tower. A man standing at the top of the tower observes a car at an angle of depression of 30\u00b0, which is approaching the foot of the tower with a uniform speed. Six seconds later, the angle of depression of the car is found to be 60\u00b0. Find the time taken by the car to reach the foot of the tower from this point. \nSolution: \nLet AB be a tower and a man be at A. \n \nA man observes a car at D at an angle of depression of 30\u00b0 \ni.e., \u2220EAD = 30\u00b0 \n\u21d2 \u2220EAD = 30\u00b0 [Both are alternate angels; AE || BD and AD cutsthen at A and D] \nThe car is approaching towards B with a uniform speed. After travelling for 6 seconds let the car be at C. \nFrom A, the angle of depression of the car at C is 60\u00b0. \ni.e., \u2220EAC= 60\u00b0 \n\u21d2 \u2220EAC = \u2220ACB \n[Both are alternate angles; AE || BD and AC cuts them at A and C] \nIn right triangle ABC, we have, \n \nFrom equations (i) and (ii), we get \n \nLet V be the velocity of the car \nNow in 6 sec distance covered = CD \n <\/p>\n
Question 16. \nThe angles of elevation of the top of a tower from two points at a distance of 4 m and 9 m from the base of the tower and in the same straight line with it are complementary. Prove that the height of the tower is 6 m. \nSolution: \nAngles are complementary. \n\u2220DAC = 9 \nand \u2220DBC = 90\u00b0 – 0 \nIn \u2206DBC, \n \nHence, height of tower is 6m Hence Proved.<\/p>\n","protected":false},"excerpt":{"rendered":"
These NCERT Solutions for Class 10 Maths Chapter 9 Some Applications of Trigonometry Ex 9.1 Questions and Answers are prepared by our highly skilled subject experts. NCERT Solutions for Class 10 Maths Chapter 9 Some Applications of Trigonometry Exercise 9.1 Question 1. A circus artist is climbing a 20 m long rope, which is tightly …<\/p>\n
NCERT Solutions for Class 10 Maths Chapter 9 Some Applications of Trigonometry Ex 9.1<\/span> Read More »<\/a><\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","spay_email":""},"categories":[2],"tags":[],"yoast_head":"\nNCERT Solutions for Class 10 Maths Chapter 9 Some Applications of Trigonometry Ex 9.1 - MCQ Questions<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n