(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A train starts at a railway station and accelerates, at a constant rate, for 7 seconds, to a velocity of 115 kilometers per hour east. Set t = 0 at the instant the train starts to accelerate.

a) determine the acceleration of the train (in km/hr/sec.) at t = 3.5 sec.

b) determine the distance, in meters, the train travels during the first 3.5 seconds of the acceleration period.

c) determine the distance, in meters, the train travels during the second 3.5 seconds of the acceleration period.

2. Relevant equations

To find the acceleration at t = 3.5 sec., I write: accel. = change in veloc. divided by change in time = 115 km/hr. - 0 km/hr.

_____________________ = 115 km/hr.

7 sec. - 0 s __________ = 16.4 km/hr/sec. constant

7 sec.

Then, to determine distance traveled in the first 3.5 seconds, i use the equation:

x = initial x + initial veloc. X time + 1/2 accel. X time squared

x = 0m + 0m/squ X 3.5 sec. + 1/2 X 4.5 m/sec squared X (3.5 sec.) squared

4.5 m is from converting the 16.4 km/hr/sec to meters.

I think I use the same equation to find the distance the train travels in the second 3.5 seconds.

Im confused about which numbers to use in the equation.

3. The attempt at a solution

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: I need help with a distance problem involving constant acceleration

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