A street lamp is fixed on a lamp-post at a height of 3.3 m from the ground. A boy 110 cm tall walks away from the base of this lamp post at a speed of 0.8 m/s. The length of the shadow of the boy after 4 seconds is:
1.1 m
1.6 m
2.1 m
2.6 m
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Question

A street lamp is fixed on a lamp-post at a height of 3.3 m from the ground. A boy 110 cm tall walks away from the base of this lamp post at a speed of 0.8 m/s. The length of the shadow of the boy after 4 seconds is:
1.1 m
1.6 m
2.1 m
2.6 m

Similarity

2 Likes

KnowledgeBoat · Accepted Answer

Let AB = 3.3 m be the lamp post and QP = 1.1 m be the position of boy after 4 seconds. AP is the distance moved in 4s at 0.8m/s = 4(0.8) = 3.2 m PM is the length of the shadow of boy. In triangle AMB and PMQ, ∠MAB = ∠MPQ = 90° ∠AMB = ∠PMQ [Common angle] ΔAMB ΔPMQ [By AA similarity]. Then ratios of corresponding sides of similar triangles are equal. Hence, option 2 is the correct option.

Mathematics

A street lamp is fixed on a lamp-post at a height of 3.3 m from the ground. A boy 110 cm tall walks away from the base of this lamp post at a speed of 0.8 m/s. The length of the shadow of the boy after 4 seconds is:
1.1 m
1.6 m
2.1 m
2.6 m

Similarity

Related Questions

In the given figure, ∠CAB = 90° and AD ⟂ BC. If AC = 75 cm, AB = 1 m and BC = 1.25 m, then AD equals:
50 cm
60 cm
65 cm
70 cm

The lengths of the sides of triangle P are 3, 4 and 5 units. Another triangle Q, which is similar to P, has one side of length 60 units, what is the smallest possible perimeter of triangle Q?
120 units
144 units
180 units
240 units

Mathematics

A street lamp is fixed on a lamp-post at a height of 3.3 m from the ground. A boy 110 cm tall walks away from the base of this lamp post at a speed of 0.8 m/s. The length of the shadow of the boy after 4 seconds is:1.1 m1.6 m2.1 m2.6 m

Similarity

Related Questions

In the given figure, ∠CAB = 90° and AD ⟂ BC. If AC = 75 cm, AB = 1 m and BC = 1.25 m, then AD equals:50 cm60 cm65 cm70 cm

The lengths of the sides of triangle P are 3, 4 and 5 units. Another triangle Q, which is similar to P, has one side of length 60 units, what is the smallest possible perimeter of triangle Q?120 units144 units180 units240 units

A street lamp is fixed on a lamp-post at a height of 3.3 m from the ground. A boy 110 cm tall walks away from the base of this lamp post at a speed of 0.8 m/s. The length of the shadow of the boy after 4 seconds is:
1.1 m
1.6 m
2.1 m
2.6 m

In the given figure, ∠CAB = 90° and AD ⟂ BC. If AC = 75 cm, AB = 1 m and BC = 1.25 m, then AD equals:
50 cm
60 cm
65 cm
70 cm

The lengths of the sides of triangle P are 3, 4 and 5 units. Another triangle Q, which is similar to P, has one side of length 60 units, what is the smallest possible perimeter of triangle Q?
120 units
144 units
180 units
240 units