A diver comes off a board with arms straight up and legs straight down, giving h

Question

A diver comes off a board with arms straight up and legs straight down, giving her a moment of inertia about her rotation axis of 18kg?m2. She then tucks into a small ball, decreasing this moment of inertia to 3.6kg?m2. While tucked, she makes two complete revolutions in 1.2s .

Part A

If she hadn't tucked at all, how many revolutions would she have made in the 1.8s from board to water?

Express your answer using two significant figures.

SubmitMy AnswersGive Up

A diver comes off a board with arms straight up and legs straight down, giving her a moment of inertia about her rotation axis of 18kg?m2. She then tucks into a small ball, decreasing this moment of inertia to 3.6kg?m2. While tucked, she makes two complete revolutions in 1.2s .

Part A

If she hadn't tucked at all, how many revolutions would she have made in the 1.8s from board to water?

Express your answer using two significant figures.

SubmitMy AnswersGive Up

Explanation / Answer

Here ,

angular speed while tucked in, w1 = 2/1.2

w1 = 1.67 rev/s

Now, using conservtaion of angular mometnum ,

I1 * w1 = I2 * w2

1.67 * 3.6 = 18 * w2

w2 = 0.33 rev/s

Now, for t = 1.8 s

no. of revolution = 1.8 * 0.33

no. of revolution = 0.6 rev/s

the number of revolutions is 0.6 rev/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.