Alexa is pushing a construction barrel up a ramp 4 feet long into the back of a truck. She is using a force of 120 pounds in a horizontal direction and the ramp is 45 degrees from the horizontal. How much work is Alexa doing?

Alexa did about 339.41 foot-pound of work in moving the barrel up the ramp.

Step-by-step explanation:

Work done is defined as the dot product of Force and displacement i.e.

W = F.d

Expanding the dot product, we get:

W = Fd cos(Ф)

Here,

W is the amount of work done, F is the Force applied, d is the displacement and Ф is the angle made by Force F with the horizontal. If we observe the given statement we can clearly see that:

Force applied = F = 120 pounds

Displacement = d = 4 feet

Angle of F with horizontal = Ф = 45 degrees

Substituting the values in the formula we get:

W = 120 x 4 x cos(45)

W = 339.41 foot-pound

This means, Alexa did about 339.41 foot-pound of work in moving the barrel up the ramp.

25

step-by-step explanation:

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°