Final answer:
To calculate the work done by the 170 N force on the block, the horizontal component of the force is used because only this component does work in the direction of displacement. The work done by the force is the product of this horizontal force component and the displacement of the block.
Step-by-step explanation:
A student asked how to determine the work done by a 170 N force dragging a 16.2 kg block over a rough, horizontal surface with a coefficient of kinetic friction of 0.115, where the force is applied at an angle of 32 degrees above the horizontal, and the block is displaced 78.5 m.
To find this, we can use the work-energy principle which states that work done is equal to the force times the distance moved in the direction of the force. Since the force is applied at an angle, we first find the horizontal component of the force which actually does work in the direction of the displacement:
- Horizontal force component (Fhorizontal) = 170 N × cos(32°)
- Work done by the horizontal force (W) = Fhorizontal × displacement
To find the work done by the 170 N force on the block, the applied force is broken down into horizontal and vertical components. Only the horizontal component does work in this scenario. As friction is a non-conservative force and does not contribute to work done in the direction of the displacement (it does negative work), it will not be considered in the calculation of work by the applied force.
Therefore, using the horizontal force component, the work done by the applied force is:
W = Fhorizontal × displacement = (170 N × cos(32°)) × 78.5 m
After completing the calculation, we get the final value of work done by the 170 N force on the block.