Answer
Stopping a truck when it's lightly loaded is easier because it has less KE compared to when it has a massive load.
The work required is the change in KE, and this is less when there is less mass.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.