Question

Now a days, buildings are constructed by following all the

fire safety norms. But the building which were

constructed far back, not according to the norms, are to

be upgraded accordingly. A school building which was

constructed in 1974 for development of the locality and

children, did not follow the norms and caught fire due to

improper electrification. The height of the building was

120 m. One day, all of a sudden fire broke out at the

middle of the building. Fireman came and placed the

ladder at a distance of 50 m away from the foot of the

building.

i) What should be the shortest length of the connecting

support base so that the fireman reaches the building

where fire broke out​

Answer 1

Answer:

130

Step-by-step explanation:

Now a days, buildings are constructed by following all the Learning Outcome:

fire safety norms. But the building which were 1. Identification of

constructed far back, not according to the norms, are to shapes.

be upgraded accordingly. A school building which was

constructed in 1974 for development of the locality and

children, did not follow the norms and caught fire due to

improper electrification. The height of the building was

120 m. One day, all of a sudden fire broke out at the

2. Application of formulae

for finding the length

of the ladder.

3. Computing ability of

height, distance and

middle of the building. Fireman came and placed the ratio.

ladder at a distance of 50 m away from the foot of the

building.

i)What should be the shortest length of the connecting

support base so that the fireman reaches the building

where fire broke out.

i) How will he place the connecting support base with

respect to ground?

(a) Parallel to the ground.

(6) Perpendicular to the inclined ladder.

(c) Parallel to the building

(d) Inclined at an angle 45° from the ground.

Hi) Mark the point in the figure (including the ladder) to

show the position of the support base and find the

ratio in which it divides the ladder.

Answer 2

The shortest length of the support base to be used by the fireman should be 79 m.

Given:
Height of the building $=120m$

Distance of ladder from the base $=50m$

To find:

Length of the support base.

Solution:

We have been given that the building is of height $120m$ and fire broke out at exactly middle of the building lets say at point A from the foot of the ground B. Hence,

$AB=\frac{120}{2}=60m$

It is also given that the fireman put the ladder $50m$ away from the foot of the building lets say at point D on the ground. Hence,

$BD=50m$

If we see this from the diagram, we notice that a triangle is formed between the fireman D, foot of the building B and the point A at which fire is broken and the building makes a right angle with the ground.

Hence, in Δ$ABD$, applying Pythagoras theorem, we get,

$AD^{2}= AB^{2}+ BD^{2}$

Substituting the known values, we get

$AD^{2}= (60)^{2}+ (50)^{2}$

$AD^{2} =3600+2500$

$AD^{2} =6100$

$AD$ ≈ $79m$

Final answer:

Hence, the shortest length of the support base to be used by the fireman should be 79 m.