3) A sports car accelerats from 60km/h to 90hm/h in 5s and then from 90km/h to 120km/h in a further 7s . What is the average acceleration of the sports can ?
A 5ms-2 , B 2.78ms-2 , C 1.43ms-2 , D 1.39ms-2 , Ans = D
Position and Movement Question 3
2007-02-26 9:42 pm
回答 (1)
2007-02-26 9:56 pm
✔ 最佳答案
change 60km/h into ms-160 X 1000/3600 = 16.67
90 x 1000/3600 = 25
120 x 1000/3600 = 33.33
The quesiton ask for the average acceleration fo the sports car,
therefore it is a = initial and final / time taken
33.33 - 16.67 / (5+7) = 1.39ms-2
therefore the ans is D
參考: me
收錄日期: 2021-04-13 15:13:56
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