Activity 6.4.1. Work Warmup.
You push a heavy box across the ground at constant speed, as shown in the free-body diagram below. Is the work done by each force positive, negative, or zero?
Section 6.4 Practice - Work
Exercises Practice Activities
Activity 6.4.2. Revisit: The Crate on Top of the Truck.
Recall The Crate on Top of the Truck.
Draw a free-body diagram for the crate. Make a qualitative Work Table indicating the direction of each force, the direction of the corresponding displacement, and the sign of the work done by each force
Activity 6.4.3. Revisit: The Brick against the Railing.
Recall The Brick against the Rail.
Assume you pull on the rope with tension \(T\) at the angle shown so the acceleration of the brick is to the left, causing the brick to slide a total distance \(d\text{.}\) Draw a free-body diagram for the brick. Make a quantitative Work Table indicating the direction of each force, the direction of the corresponding displacement, and the sign of the work done by each force
Activity 6.4.4. Pushing Books.
Two books on the same frictionless surface are pushed toward each other; consider the system of both books. Assume each hand pushes with the same constant force \(F^H\) and that each book moves the same distance \(d_b\text{.}\) Draw a free-body diagram for the system. Make a quantitative Work Table indicating the direction of each force, the direction of the corresponding displacement, and the work done by each force
Activity 6.4.5. Work Tables.
For each situation: (1) draw a free-body diagram, (2) make a qualitative Work Table to determine if the work done by each force is positive, negative, or zero, and (3) determine if the net work is positive, negative, or zero
- An elevator moves downward at constant speed (system = elevator).
- A ball has been thrown and travels upward in a straight line (system = ball).
- A sled slides to a stop while traveling up a rocky slope (system = sled).
References References
[1]
“Pushing Blocks” activity adapted from Tutorials in Introductory Physics.
