Your 'cq_1_03.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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The problem:
A ball starts with velocity 0 and accelerates down a ramp of length 30 cm, covering the distance in 5 seconds.
• What is its average velocity?
Average velocity = distance / time
Avg V = 30 cm / 5 sec
Avg V = 6 cm / sec
answer/question/discussion:
• If the acceleration of the ball is uniform then its average velocity is equal to the average of its initial and final velocities.
We can assume that the acceleration is constant, which means that the velocity is increasing at an increasing rate. Therefore, the average velocity is equal to the average of its initial and final velocities.
answer/question/discussion:
• You know its average velocity, and you know the initial velocity is zero. What therefore must be the final velocity?
Final velocity equals the average velocity multiplied by 2. The average velocity calculated earlier was 6 cm /sec. Therefore, the final velocity is 12 cm / sec.
answer/question/discussion:
• By how much did its velocity therefore change?
The velocity went from rest to 12 cm / sec. The change from final velocity to initial velocity was 12 cm / sec – 0 cm / sec. That equals a change of 12 cm / sec.
answer/question/discussion:
• At what average rate did its velocity change with respect to clock time?
Acceleration is a change in velocity over a change in time. We know that the total change in velocity was 12 cm / sec and there was a time lapse of 5 seconds.
Average Acceleration = (12 cm / sec – 0 cm sec) / (5 sec – 0 sec)
Avg A = (12 cm / sec) / (5 sec)
Avg A = 2.4 cm / sec squared
answer/question/discussion:
• What would a graph of its velocity vs. clock time look like? Give the best description you can.
We know that the acceleration is constant, so the slope of the graph would be constant. This would mean that the graph is linear. We know it would be a positive linear slope because the velocity increases as time increases.
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15 minutes
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&#Very good work. Let me know if you have questions. &#