Jordan M.

asked • 12/13/21

Physics energy of pendelum

A 16.9 kg monkey is swinging on a

5.32 m long vine. It starts at rest,

with the vine at a 43.0° angle.

How fast is the monkey moving at

the bottom of its swing?

-I’m loooking for the speed of the monkey at the bottom of the swing in m/s,I would greatly appreciate the help

Grigoriy S.

tutor
Please try to show the picture like this: Position 1 of the pendulum at point A, when it makes angle Θ = 35° with the vertical. Position 2 - it is when the pendulum at point C (equilibrium position, and the bob of the pendulum is at a lowest possible level. Label point O - it is the point where we hang up the pendulum; and point B - where vertical is crossed by the horizontal line, that goes through point A. We can write the law of conservation of mechanical energy E1 = E2 Here E1 - total mechanical energy at position 1; and E2 - total mechanical energy of the pendulum at position 2. Let's select the zeroth's level of energy point 2. Then at point 1 the body has only potential energy E1 = mgh ( here h = CB). At point 2 the body has only kinetic energy E2 = 1/2 mv2 . Now we write mgh = 1/2 mv2. From this equation h = v2 / 2g. Using geometry, we see that h = CO - BO CO = L - length of the pendulum. BO - leg of the right triangle ABO ( right angle is angle ABO), hence BO = AO·cos Θ or BO = Lcos Θ Finally, h = L - Lcos Θ = L(1 - cos Θ). Now we can write L(1 - cos Θ) = v2 / 2g From this equation we will have for length of the pendulum L = v2 /2g (1 - cos Θ) Putting numerical values to this formula ( and g = 10 m/s2 ), we will have L = 3.2 m Now you look for the answer that is the closest to yours. It is (a)!
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12/14/21

Grigoriy S.

tutor
In your case you need to find velocity it will be v= √(2gl(1-cosθ)
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12/14/21

1 Expert Answer

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Grigoriy S. answered • 12/14/21

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I have already showed the solution of similar problem in this rubric. Please check it out. It is about finding the length of the pendulum.

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Jordan M.

Sir I’m not aware of you what you mean ,I am just looking for an answer for the problem
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12/14/21

Grigoriy S.

tutor
Please find my profile, you then click Examples of expertise, and you will find the problem that l placed today in Physics Section. It is also about pendulum and similar to yours
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12/14/21

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