Question

Review Conceptual Example 7 before starting this problem. A uniform plank of length 5.0 m and weight 225 N rests horizontally on two supports, with 1.1 m of the plank hanging over the right support (see the drawing). To what distance x can a person who weighs 385 N walk on the overhanging part of the plank before it just begins to tip?

Answer 1

Answer:

0.82 m

Explanation:

We are given that

Weight,$w_1$=225 N

Length,l=5 m

d=1.1 m

We have to find the distance x  for which person weighs 385 N walk on the overhanging part of the plank before it just begins to tip.

Half length=$\frac{l}{2}=\frac{5}{2}=2.5 m$

$r=\frac{l}{2}-d=2.5-1.1=1.4 m$

$w_2=385 N$

When system in equilibrium then

$w_1r=w_2 x$

$225\times 1.4=385\times x$

$x=\frac{225\times 1.4}{385}$

$x=0.82 m$