Phy 121
Your 'cq_1_25.1' 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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A steel ball of mass 110 grams moves with a speed of 30 cm / second around a circle of radius 20 cm.
What are the magnitude and direction of the centripetal acceleration of the ball?
answer/question/discussion: cent a = v^2/r = (30cm/s)^2 / 20cm = 45cm/s^2
What is the magnitude and direction of the centripetal force required to keep it moving around this circle?
answer/question/discussion: 2pir^2 = 2*3.14*20^2 = 2512
Then 2512/30 = 87.7cm/s^2
by Newton's Second Law, centripetal force = mass * centripetal acceleration = 110 grams * 45 cm/s^2 = 50,000 g cm/s^2= 50,000 dynes or about .5 kg m/s^2 = .5 Newtons.
The centripetal acceleration is directed toward the center of the circle, and the centripetal force is therefore toward the center of the circle.
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15min
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i wasn't sure where to start on these, i didn't see any notes or book chapters for this topic
You got the acceleration; you could have gotten the force (see my notes, which you will understand).