SOLUTION: jA car accelerated from 25 km/hr to 55 km/hr in 30 seconds. What is its acceleration?

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Question 1197727: jA car accelerated from 25 km/hr to 55 km/hr in 30 seconds. What is its acceleration?
Found 3 solutions by ikleyn, MathLover1, Alan3354:
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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A car accelerated from 25 km/hr to 55 km/hr in 30 seconds. What is its acceleration?
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By the definition, an acceleration is the change of speed related to the change of time

    a = %2855-25%29%2F%28%281%2F120%29%29 = 30*120 = 3600 km/hr^2.


Here 1/120 represents 30 seconds, that comprise  1/120 of an hour.

Solved.



Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!



the acceleration of the body is given by:
a=%28v-u%29%2Ft
where t is the time taken to change the initial velocity u to final velocity v.
given:
u=25%28+km%2Fh%29
v=55%28+km%2Fh%29
t=30s
The initial velocity in m%2Fs :
u=25%2A%281000%2F3600%29%28m%2Fs%29=%28125%2F18%29%28m%2Fs%29
The final velocity in m%2Fs:
v=55%2A%281000%2F3600%29%28m%2Fs%29=%28275%2F18%29%28m%2Fs%29

Plugging in all given values, we have
a=%28%28275%2F18%29%28m%2Fs%29-%28125%2F18%29%28m%2Fs%29%29%2F30s
a=%28%2825m%2F3s%29%29%2F30s
a=0.278%28+m%2Fs%5E2%29


Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
jA car accelerated from 25 km/hr to 55 km/hr in 30 seconds. What is its acceleration?
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It's (55 - 25)/30 km/hr per second.
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If you want to spec units, then say that.