To express the force vector F in terms of the unit vectors i and j, we need to break down the force into its horizontal and vertical components.
Given that the child pulls the wagon with a force of 31 lbs at an angle of 45 degrees with the ground, we can determine the horizontal and vertical components of the force as follows:
Horizontal component: Fx = F * cos(θ)
Vertical component: Fy = F * sin(θ)
Where:
F is the magnitude of the force (31 lbs)
θ is the angle between the force and the ground (45 degrees)
Substituting the given values into the equations, we have:
Fx = 31 lbs * cos(45°)
Fy = 31 lbs * sin(45°)
Using the approximation values for cosine and sine of 45 degrees:
Fx ≈ 31 lbs * 0.7071
Fy ≈ 31 lbs * 0.7071
Simplifying:
Fx ≈ 21.92 lbs
Fy ≈ 21.92 lbs
Therefore, the force vector F can be expressed as:
F ≈ 21.92 lbs * i + 21.92 lbs * j