1. If you travel 7000 m at a rate of 25 m/s and, how long does it take to complete the trip?
2. How long does it take to get back?
3. What is the total time for your trip there and back?
回答 (6)
1.
Time taken for the trip
= Distance / Rate
= 7000/25 s
= 280 s
= 4 min 40 s
2.
If the rate is unchanged, time taken to get back
= Distance / Rate
= 7000/25 s
= 280 s
= 4 min 40 s
3.
Total time for the trip there and back
= 280 × 2 s
= 560 s
= 9 min 20 s
7000m is your 'given', start there:
7000m (1sec/25m) = 280 s
There and back just doubles the time: 560 s
((note: in KMS system, time is reported in seconds))
time for getting there = tf = 7000 m / 25 m/sec = 280 sec
time for getting back = tr = 7000 m / 25 m/sec = 280 sec
total trip time t = tf+tr = 280+280 = 560 sec (a bit less than 10 min)
I must make a comment on the answer given. How are you going to go from +25 m/s to -25 m/s without taking some time to do so? There will be a discrepancy between what is possible and what the question asks.
7000/25=280s.
If the speed is the same 280s.
total time 560s= 9.33min.=9m 19.8s.
Do you know, I was not good at maths at school in the 1960s, but I could do that sum in my head, and write down my workings just to make sure.
收錄日期: 2021-04-24 07:58:46
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