contestada

A worker pushes a large rock to the north while another worker helps by pushing it to the east. If they both exert equal force, in what direction does the rock move?
Question 2 options:

northeast

east

north

southwest

Respuesta :

let the magnitude of force applied by each worker be "F"

consider east-west direction along X-axis and north-south direction along Y-axis

In unit vector form, force vector by worker pushing in east direction is given as

[tex]\underset{A}{\rightarrow}[/tex] = F [tex]\hat{i}[/tex] + 0  [tex]\hat{j}[/tex]


In unit vector form, force vector by worker pushing in north direction is given as

[tex]\underset{B}{\rightarrow}[/tex] = 0 [tex]\hat{i}[/tex] + F  [tex]\hat{j}[/tex]

resultant force is given as the vector sum of two vector forces as

[tex]\underset{R}{\rightarrow}[/tex] = [tex]\underset{A}{\rightarrow}[/tex] + [tex]\underset{B}{\rightarrow}[/tex]

[tex]\underset{R}{\rightarrow}[/tex] = (F [tex]\hat{i}[/tex] + 0  [tex]\hat{j}[/tex] ) + (0 [tex]\hat{i}[/tex] + F  [tex]\hat{j}[/tex] )

[tex]\underset{R}{\rightarrow}[/tex] = F [tex]\hat{i}[/tex] +  F  [tex]\hat{j}[/tex]

direction of the force is hence given as

θ = tan⁻¹(F/F)

θ =  tan⁻¹(1)

θ = 45 degree north of east

hence the direction is north-east