Question: joule is unit of. in mks system
[{'answer': 'energy', 'provenance': [{'wikipedia_id': '16327', 'title': 'Joule', 'start_paragraph_id': 1, 'start_character': 46, 'end_paragraph_id': 1, 'end_character': 52, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '16327', 'title': 'Joule', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 498, 'bleu_score': 0.8543527564301251, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15494346757818329411}, 'section': 'Section::::Abstract.'}]}]