Question

A 20.0-kg uniform plank (10.0 m long) is supported by the floor at one end and by a vertical rope at the other as shown in the figure. A 50.0-kg mass person stands on the plank a distance three-fourths of the length plank from the end on the floor.

Answer 1

Answer:

Tension= 475N

Force= 225N

Explanation:

The question is not complete, here is the complete question

Also, see attached a free body diagram for your reference

"A 20.0-kg uniform plank is supported by the floor at one end by a vertical rope at the other as shown in the figure. A 50.0-kg mass person stands on the plank a distance three-fourths of the length plank from the end on the floor.

a. What is the tension in the rope?

b. What is the magnitude of the force that the floor exerts on the plank?"

given data

mass of man=50kg

mass of plank=20kg

length of plank=10m

let us make the lenght of the rope be d

The torque about the floor

That is taking moment about the floor

$N*0+T*d=20*10*d/2 + 50*10*3d/4\\\\T=100+375=475N$

Force will be also zero  

$N+T=20*10+50*10\\\\N+T=700 \\\\N=700-475=225 newtons\\\\N+T=20*10+50*10\\\\N+T=700\\\\N=700-475=225newtons$