2. An automobile traveling along a straight road increases its speed from 30.0 m/s to 50.0 m/s in a distance of 180 m. If the acceleration is constant, how much time elapses while the auto moves this distance?
2007-09-12 15:02:07 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Let's get some limits. At 30 m/s, it takes 6 seconds. At 50 m/s, it would take 3.6 seconds.
If the acceleration were constant, relative to distance, it would be 40 m/s average speed, and the time would be 4.8 seconds. However, it's constant relative to *time*, which means that it will travel the second half of that distance much more quickly than the first half.
What you need to do is to find the average speed during that 180 seconds. It's the *geometric* mean you're looking for, not the *arithmetic* mean.
2007-09-12 15:13:44 · answer #1 · answered by Anonymous · 0⤊ 0⤋
You solve it by remembering that
v²=v0²+2ax to get a. Then
v=vo+at to find the time.
HTH
Doug
2007-09-12 15:08:54 · answer #2 · answered by doug_donaghue 7 · 1⤊ 0⤋
phyzzics suks
2015-12-16 15:57:45 · answer #3 · answered by Matthew 1 · 0⤊ 0⤋
i wish i knew physics...
2007-09-12 15:09:07 · answer #4 · answered by reader 3 · 0⤊ 0⤋