Home
Class 12
MATHS
A lamp is on the top of the lamp post of...

A lamp is on the top of the lamp post of height 2a metres situated on a straight road. A boy of height a metre walks towards the post of the speed of c metre/minute. Find the rate of decrease of the shadow.

Text Solution

Verified by Experts

The correct Answer is:
the rate of decrease is metre/minute
Promotional Banner

Similar Questions

Explore conceptually related problems

A lamp is on the top of a lamp post of height 2a metres situated on a straight road. A boy of height a metre walks towards the post at the speed of c metre/minute. Find the rate of decrease of the lengh of his shadow.

A man of height 2 metres walks at a uniform speed of 5 km/h away from a lamp post which is 6 metres high. Find the rate at which the length of his shadow increases.

The heights of two towers are 210 metres and 70 metres respectively. If the angle of elevation of the top of the first twoere form the bottom of the second tower be 60^@ , then find the angle of elevation of the top of the scecond tower from the bottom of the first tower.

As seen from the deck of a ship the angle of elevations of the top and bottom of light house situated on the seaside are 60^@ and 30^@ . If the lgiht house is located 8 metre above the sea level and the deck of the ship[ is at a height of 3 metre from sea level, then what is the height of the light house?

If it costs Rs. 41.25 to polish the curved surface of a cylindrical pillar of height 15 metres at the rate of 25 paise per square-metre, then find the radius of its base.

To a person standing at the middle point of the horizontal straight line joining the feet of two vertical posts of the same height, the angle of elevation of the top of each post appears to be 30^@ . After walking 40metres towards one of them , the person observes that the angle of elevation of the top of the same post has changed to 60^@ . Find the distance between the two posts.

A man 6 ft tall walks away from the foot of a lamp-post 15 ft high at the rate of 3 mi/h how fast does the tip of his shadow move?

The length of a flag at the roof of three storied building is 3.3 metres. From any point of road, the angles of elevation of the top and the foot of the falgspot are 50^@ and 45^@ . Find the height of the three-storied building . [tan50^@ = 1.192]

Two houses stand just on the opposite sides of a road of a village. A ladder that stands against the wall of the first house is at a distance of 6 metres from the house and makes an angle of 30^(@) with the horizontal line.But if the ladder stands against the wall of the second house keeping its foot at the same point, it makes an angle of 60^(@) with the horizontal line. (a) Find the length of the ladder. (b) Calculate the distance of the foot of the ladder from the foot of the wall of the second house. (c) Find the width of the road. Find the height where the top of the ladder is fixed against the wall of the second house.

A 5 ft long man walks away from the foot of a 12 1/2 ft high lamp post at the rate of 3 mile/h. Find the rate at which his shadow is increasing.