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01112009  #1 
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Please help, Can't figure this out!
What is the acceleration produced on an object if it changes its velocity from 36 cm/min to 288 m/h in 10 min ?
And A driver was driving a car weighing 500 kg towards his home, covering a distance of 100 km in one hour. He realizes that he is late for a party and accelerates the motion of the car. After 10 minutes he is covering a distance of 2 km in one minute. How much force did the engine apply on the car to achieve the acceleration? I am a graduate student majoring in early childhood education and I am required to take a science course. I took an "easy" course so I thought! I tried for hours to figure these questions out and I can't. Thank you for all your help! 
01122009  #2  
Join Date: Dec 2008
Posts: 249

Quote:
a = delta v / delta t where delta means "change in" First you need to make your starting velocity and ending velocity have the same units. Therefore, 288 m/h = 288 m/h x (1 hr/60 min) x (100 cm/1 m) = 480 cm/min Change in velocity = 480 cm/min  36 cm/min = 444 cm/min Change in time = 10 min accel = (444 cm/min) / (10 min) = 44.4 cm/min^2 (or 44.4 cm/min/min) 2. First find the acceleration as in problem 1. 100 km/hr = 100 km/hr x (1 hr/60 min) = 1.666667 km/min Change in velocity = 2 km/min  1.6666 km/min = 0.33333 km/min Change in time = 10 min accel = (0.33333 km/min) / (10 min) = 0.0333333 km/min^2 Now remember force = mass x acceleration = f =ma So f = (500 kg) x (0.0333333 km/min^2) = 16.66667 kgkm/min^2 Units of force are Newtons (N) which are kg x m/sec^2 so converting gives: 16.6666667 kgkm/min^2 x (1 min/60 sec) x (1 min/60 sec) x (1000 m/1 km) = 4.63 N Hope this helps. 

01122009  #3 
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I am assuming that you are using the SI units.
1. Convert the first and second velocity to m/s and the time to seconds. Then apply what acceleration is defined as. 
01132009  #4 
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Thank you all for your help! I went to class the next day and we were all going crazy. I appreciate all of your help

03192009  #5 
Join Date: Mar 2009
Posts: 4

Similar Question
What are the odds? I was looking for the answer to a similar question for something that my nephew couldn't figure out! Wow!
Thanks for the answers guys... 
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