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2 years ago

Please help!

Physics

1 answer:

FinnZ [79.3K]2 years ago

5 0

(A) The speed of the pendulum when it reaches the bottom is 3.83 m/s.

(B) The speed of the pendulum when it reaches the bottom after losing 18% of its energy is 3.47 m/s.

(D) When the pendulum stops swinging, it has used all its energy to overcome frictional force of air.

<h3>Speed of the pendulum when it reaches the bottom</h3>

Apply the principle of conservation of energy;

K.E = P.E

¹/₂mv² = mgh

v² = 2gh

v = √2gh

v = √(2 x 9.8 x 0.75)

v = 3.83 m/s

<h3>Speed pendulum after losing 18% of the its initial energy</h3>

K.E = (100 - 18)P.E

¹/₂mv² = 0.82mgh

V = √(0.82 x 2gh)

v = √(0.82 x 2 x 9.8 x 0.75)

v = 3.47 m/s

<h3>Height reached when its looses another 7%</h3>

K.E = 0.5(1)(3.47)² = 6.02 J

When it losses 7% = 6.02 - (0.07 x 6.02) = 5.598 J

Height reached:

mgh = 5.598

h = 5.598/mg

h = 5.598/(1 x 9.8)

h = 0.57 m

<h3>Final energy of the pendulum</h3>

When the pendulum stops swinging, it has used all its energy to overcome frictional force of air.

Thus, the speed of the pendulum when it reaches the bottom is 3.83 m/s.

The speed of the pendulum when it reaches the bottom after losing 18% of its energy is 3.47 m/s.

The height reached by the pendulum after losing another 7% of its energy is 0.57 m.

Learn more about speed of pendulum here: brainly.com/question/13655641

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