5 m long ladder is leaning against a wall and it reaches the wall at a point 3 m high. If the foot of the ladder is moved 2.6 m towards the wall then the distance by which the top of the ladder slides upwards on the wall is:

Question

Question

This question was previously asked in

NTPC CBT-I (Held On: 9 Jan 2021 Shift 2)

Answer 1

Given:

Length of ladder = 5 m

Concept used:

Pythagoras theorem

Calculation:

F1 Arun K 20-1-22 Savita D13

According to the question,

Distance from the wall to the foot of the ladder \(= \sqrt{5^2 - 3^2}\)

⇒ 4 m

Now it become 4 - 2.6 = 1.4 m

So height \(= \sqrt{5^2 - 1.4^2}\)

⇒ \(\sqrt{25 - 1.96}\)

⇒ \(\sqrt{23.04}\)

⇒ 4.8

So ladder slide upwards by 4.8 - 3 = 1.8 m

∴ Ladder slides upwards on the wall is 1.8 m

Download Solution PDF