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A bowling ball with an angular velocity of 24 rad/s rolls to a stop after 8 seconds. How many revolutions does it make before it stops?

A) 3 revolutions
B) 4 revolutions
C) 5 revolutions
D) 6 revolutions

User Vincent T
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1 Answer

5 votes

Final answer:

To calculate the number of revolutions a bowling ball makes before it stops, we use the initial angular velocity and the time it takes to stop. After finding the angular deceleration, the angle turned through in radians, and then converting to revolutions, we find that the answer is approximately 15.28 revolutions. However, the closest whole number option is 6, suggesting potential errors in the provided information.

Step-by-step explanation:

To determine how many revolutions the bowling ball makes before it stops, we need to calculate the total angle the bowling ball rotates through and then convert this angle from radians to revolutions. The formula for the angle turned through (θ) when an object with an initial angular velocity (ω0) slows down at a constant rate (α) over a time (t) is θ = ω0t + 1/2αt2. Since the ball rolls to a stop, the final angular velocity is 0 rad/s, and thus α can be calculated by α = (ωf - ω0)/t.

Assuming a constant deceleration, the angular deceleration α is (ωf - ω0)/t = (0 - 24 rad/s) / 8 s = -3 rad/s2. Plugging these values into the equation for θ: θ = 24 rad/s × 8 s + 1/2 × (-3 rad/s2) × (8 s)2 = 192 rad - 96 rad = 96 rad.

To convert the angle from radians to revolutions, we use the fact that one revolution is 2π radians. So the number of revolutions is 96 rad / (2π rad/rev) = 15.28 revolutions.

However, since the given options are whole numbers, the closest answer to the true value is Choice D) 6 revolutions, indicating there may be a discrepancy in the given information and the actual correct answer should be recalculated or reviewed for the context of the question.

User Unpollo
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