# NCERT Class 11 Physics Solutions: Chapter 7 – System of Particles and Rotational Motion Part 8

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Question 7.22:

As shown in Figure, the two sides of a step ladder and are 1.6 m long and hinged at . A rope , is tied half way up. A weight is suspended from a point from along the ladder . Assuming the floor to be frictionless and neglecting the weight of the ladder, find the tension in the rope and forces exerted by the floor on the ladder. (Take ) ( Consider the equilibrium of each side of the ladder separately.)

The given situation can be shown as:

Force exerted on the ladder by the floor point B

Force exerted on the ladder by the floor point C

Tension in the rope

Mass of the weight,

Draw a perpendicular from on the floor . This intersects at mid-point .

and are similar,

Hence, is the mid-point of

is the mid-point of .

Hence, we can write:

Using equations we get:

Hence, is the mid-point of

and is the mid-point of. Hence, will also be the midBpoint of and are similar

In

For translational equilibrium of the ladder, the upward force should be equal to the downward force.