Acceleration equations involving time.

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A car accelerates at 1.7 m/s², and the discussion revolves around calculating the time taken to accelerate from 90 km/hr to 110 km/hr. The initial and final velocities are converted from km/hr to m/s, resulting in a change of 6 m/s. The formula used is T = (Vf - Vi) / A, leading to the calculation of time. Participants emphasize the importance of unit conversion and rounding during calculations. The final answer for the time taken is confirmed to be correct if rounded appropriately.
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At highway speeds, a certain car is capable of an an acceleration of about 1.7 m/s^2. At this rate, how long does it take to accelerate from 90 km/hr to 110 km/hr? (WATCH UNITS.)

Given- Time=?
A=1.7m/s^2
Vi=90km/hr
Vf=110km/hr


Vf=vi+at Solve for t! T= vf-vi/a 110km/hr-90km/hr = 20km/hr
1.7m/s^2

How do I divide 20km/hr by 1.7 m/s^2?
 
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cneedshelp said:
At highway speeds, a certain car is capable of an an acceleration of about 1.7 m/s^2. At this rate, how long does it take to accelerate from 90 km/hr to 110 km/hr? (WATCH UNITS.)

Given- Time=?
A=1.7m/s^2
Vi=90km/hr
Vf=110km/hrVf=vi+at Solve for t! T= vf-vi/a 110km/hr-90km/hr = 20km/hr
1.7m/s^2

How do I divide 20km/hr by 1.7 m/s^2?

First convert your units to be in terms of meters and seconds then do the calculation.
 
bp_psy said:
First convert your units to be in terms of meters and seconds then do the calculation.

I got .02m but I'm not sure how to convert the hr to seconds
 
cneedshelp said:
I got .02m but I'm not sure how to convert the hr to seconds
What is that .02m?
You want to convert km/hr to m/s.An hour has 60 mins and a min has 60 sec.
\frac{1km}{hr}\frac{1hr}{3600s}\frac{1000m}{1km}= \frac {1000m}{3600s}
 
bp_psy said:
What is that .02m?
You want to convert km/hr to m/s.An hour has 60 mins and a min has 60 sec.
\frac{1km}{hr}\frac{1hr}{3600s}\frac{1000m}{1km}= \frac {1000m}{3600s}

What I did now was 20(1000)/3600
is 6m/s using sig figs and that's the answer! right?
 
cneedshelp said:
What I did now was 20(1000)/3600
is 6m/s using sig figs and that's the answer! right?

Yes if your teacher requires you to round up after every step.I would round after the final answer for time though.
 
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