Question

I need help with the following 3 questions I will post the other question part during our session

Answer 1

Work is defined as the force times the distance, as in the following equation:

`W=Fd`

Where:

`\begin{gathered} W=\text{ work} \\ F=\text{ force} \\ d=\text{ distance} \end{gathered}`

In the formula, the force "F" must be parallel to the movement of the object. Since the normal force and the perpendicular component of the weight are not parallel to the motion this means that these forces don't do work.

The parallel force and the force of the rope are parallel to the motion and therefore these forces do work on the crate.

The forces acting on an object are classified as internal and external. The external forces include the applied force on the object, the force of friction, the normal force, etc.,

The internal forces include the gravitational force.

The work done by the object is used to increase its potential gravitational energy, therefore, the energy in the system is conserved.

To calculate the work we will use the fact that the work is equivalent to the potential gravitational energy of the crate when it reaches the height of 3 meters. Therefore, we have:

`W=U`

Where:

`\begin{gathered} W=\text{ work} \\ U=\text{ potential gravitational energy} \end{gathered}`

The gravitational energy is determined using the following formula:

`U=\text{mgh}`

Where:

`\begin{gathered} m=\text{ mass} \\ g=\text{ acceleration of gravity} \\ h=\text{ height} \end{gathered}`

Substituting the values we get:

Solving the operations:

`U=1470J`

Therefore, the gravitational energy is 1470J, and since this is equivalent to the work, the work is also 1470 J.