please solve 178th question.

Asked by Kanwaranita10 | 4th Feb, 2020, 07:08: AM

Expert Answer:

 
 
A boy is sitting at a distance of 1 m from one end. 
Plank of see-saw is 4 m long. 
The fulcrum of the see saw will be exactly at centre of plank i.e. 2 m 
Thus, load arm is 2 - 1 = 1m 
Thus, 
Load =500 N 
Effort = 400 N 
Load arm x load = effort arm x effort 
1 x 500 = EA x 400 
Thus, 
EA = 1.25 m 
Thus, the distance at which Anu must sit from fulcrum is 1.25 m
 
By principle of moments, in equilibrium 
Anticlockwise moment = clock wise moment 

Answered by Shiwani Sawant | 4th Feb, 2020, 01:11: PM