Sure, let's analyze the task of the robotic arm step by step to understand where work is done.
1. Step 1: Grip block
- In this step, the robotic arm grips the block. There is no movement of the block against a force, so no work is done according to the physics definition of work.
2. Step 2: Lift block ten centimeters
- Here, the robotic arm lifts the block ten centimeters against the force of gravity. Work is performed whenever a force causes an object to move in the direction of the force. Since the block is being lifted, work is done during this step.
3. Step 3: Hold for twenty seconds
- During this step, the robotic arm holds the block stationary for twenty seconds. Even though force is being applied to keep the block in place, there is no displacement of the block. No work is done if there is no movement.
4. Step 4: Release block
- In this step, the robotic arm releases the block. Releasing the block does not involve moving it against a force, so no work is done in this step either.
Therefore, the step during which the robotic arm does work on the block is Step 2.
