3. a horizontal force of 20 newtons eastward causes a 10 - kilogram box to have a displacement of 5 meters…

Explanation:

Step1: Recall the work formula

The formula for work ( W ) is ( W = F \cdot d \cdot \cos\theta ), where ( F ) is the force, ( d ) is the displacement, and ( \theta ) is the angle between the force and displacement vectors.

Step2: Determine the angle

Since the force and displacement are in the same direction (eastward), ( \theta = 0^\circ ), and ( \cos(0^\circ)=1 ).

Step3: Substitute values into the formula

Given ( F = 20,\text{N} ), ( d = 5,\text{m} ), and ( \cos\theta = 1 ), we substitute into ( W = F \cdot d \cdot \cos\theta ): ( W = 20,\text{N} \times 5,\text{m} \times 1 )

Step4: Calculate the work

( 20\times5 = 100 ), so ( W = 100,\text{J} ) (joules, since ( 1,\text{J} = 1,\text{N}\cdot\text{m} )).

Answer:

The total work done is ( 100 ) joules.