Answer:
0.488 Ā m Ā
Explanation:
If Īø be the angle ladder makes with the plane
cos Īø = 1.2 / 5
Tan Īø = 4.04
Let the height a person of weight 600 N Ā can climb be h from the ground .
Distance from the base point Ā where ladder touches the floor Ā = h / tanĪø
= h / 4.04
Total reaction force = total downward force
R = 200 + 600
800 N
Frictional force = Ī¼ R
= .2 x 800
= 160 N
Taking moment of force about the point on the ladder Ā where it Ā touches the floor Ā and balancing them
200 x 1.2 x .5 + 600 x Ā h / tanĪø Ā = Ī¼ R x Ā 1.2 / tanĪø ( reaction Ā at the top point of ladder where it touches the wall is Ā Rā and
Rā =Ī¼ R Ā )
= 200 x 1.2 x .5 + 600 x Ā h / tanĪø Ā = 160 x 1.2 / tanĪø
120 Ā - 600 h / 4.04 = 47.52
120 - 47.52 = 600 h / 4.04
72.48= 148.51 h
h = 0.488 Ā m Ā
=
