# Planck energy: Quiz

Question 1: In the equations of ________, G is often multiplied by 8π.
General relativityBlack holeGravitationIntroduction to general relativity

Question 2: The ________ observed in 1991 had a measured energy of about 50 joules, equivalent to about 2.5×10−8 Ep.
Ultra-high-energy cosmic rayNeutrinoCosmic-ray observatoryGreisen–Zatsepin–Kuzmin limit

Question 3: Even so, Ep is a meaningful quantity in particle physics when ________ is taken into account.
Equivalence principleGravitationIntroduction to general relativityGeneral relativity

Question 4: Hence given Planck units, the ________ E = mc² simplifies to E = m, so that the Planck energy and mass are numerically identical.
Mass–energy equivalenceSpecial relativityPhotonLorentz ether theory

Question 5: In physics, the unit of energy in the system of natural units known as ________ is called the Planck energy, denoted by EP.
Metric systemPlanck unitsStoney scale unitsGeometrized unit system
{"ft_lang_label":"__label__en","ft_lang_prob":0.9418949,"math_prob":0.944355,"size":588,"snap":"2019-43-2019-47","text_gpt3_token_len":159,"char_repetition_ratio":0.17979452,"word_repetition_ratio":0.0,"special_character_ratio":0.33843538,"punctuation_ratio":0.14876033,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9900991,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-14T17:18:57Z\",\"WARC-Record-ID\":\"<urn:uuid:4bdb09fb-4fad-4682-906e-eca2f59911a6>\",\"Content-Length\":\"28395\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:2b30881f-1299-4e92-a584-7d59e784e7da>\",\"WARC-Concurrent-To\":\"<urn:uuid:8821f9b1-8590-48d6-b6cf-67fc0a7f6e61>\",\"WARC-IP-Address\":\"148.251.235.240\",\"WARC-Target-URI\":\"http://quiz.thefullwiki.org/Planck_energy\",\"WARC-Payload-Digest\":\"sha1:K3O3RQZJY2DC7FJBQWWVIZELKT3OL3PY\",\"WARC-Block-Digest\":\"sha1:5MQY5CSVATK75RRITXCGN6QPYH33AKZW\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496668529.43_warc_CC-MAIN-20191114154802-20191114182802-00021.warc.gz\"}"}