Long answer·Hard exam skill (4/5)·No calculator
Difficulty guide
The label describes the problem, not your ability.
1/5 - Foundational
Warm-up setup; checks one basic idea.
2/5 - Routine exam skill
Normal syllabus skill; usually one main rule or interpretation.
3/5 - Standard multi-step
Exam-style problem with multiple steps or a common trap.
4/5 - Hard exam skill
High-end exam problem; combines methods carefully.
5/5 - Challenge
Stretch problem beyond normal exam pressure.
Question
A pull moves a box along a rough horizontal floor. Friction is opposite to motion.
Total: 4 marks
(a) Find the work done by the pulling force. (1 mark)
(b) Find the work done by friction. (1 mark)
(c) Find the net work done on the box. (1 mark)
(d) Explain the sign of the work done by friction. (1 mark)
Something wrong with this item?