Question

An electrician has to repair an electric fault on a pole of the height 5 m. He needs
to reach a. point 1.3 m; below the top of the pole to under take the repair work.
What should be the length of the ladder that he should use which when inclined
at an angle of 60° to the horizontal. Also how far from the foot of the pole should
he place the foot of the ladder? (Take V3 = 1.73 )​

Answer 1

Answer:

The answer will be :

Hieght of ladder = approx. 1.5 m.

Base of ladder from the foot of the pole = approx. 0.75m.

Step-by-step explanation:

We have given;

Height where the electrician needs to reach = 1.3m

Angle at which the ladder inclined to ground = 60°.

and √3 = 1.73;

Hieght of the ladder will be given as;

Sine of 60° = Perpendicular / Hypotaneus

here, the hypotaneus will be the length of the ladder.

Hence, sin 60° = 1.3 / Hypotaneus;

√3/2 = 1.3 / Hypotaneus;

Hypotaneus = 1.3 *2 / √3;

Hence, height of ladder = 2.6 / 1.73;

=1.508m

= approx. 15m

Now, we have;

Perpendicular = 1.3m;

Hypotaneus = 1.5m;

Using Pythagoreas theorem, we can deduce that;

Base = √{(hypotaneus)^2 - (perpendicular)^2

= √{(1.5)^2 - (1.3)^2};

( If you are brave then calculate it on yourself )

= 0.748 m or approx. 0.75m

There's an another way of calculating this and i.e,

Tangent of 60° = Perpendicular / Base;

√3 = 1.3 / Base;

Base = 1.3 / 1.73

= approx. 0.75m

Therefore, the ladder should be placed at 0.75 m away from the foot of the pole.

That's all.