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Ivahew [28]
4 years ago
9

You've always wondered about the acceleration of the elevators in the 101-story-tall Empire State Building. One day, while visit

ing New York, you take your bathroom scale into the elevator and stand on it. The scale reads 150 lb as the door closes. The reading varies between 120 lb and 170 lb as the elevator travels 101 floors.
i)What is the maximum acceleration upward?
ii)What is the maximum magnitude of the acceleration downward
Physics
1 answer:
kondor19780726 [428]4 years ago
8 0

Answer:

(i) The maximum acceleration upward is 2.02 m/s².

(ii) The maximum acceleration downward is 1.39 m/s².

Explanation:

Let a be the maximum acceleration of the elevator.

The mass of the person at ground is 150 lb. We have to convert the mass into kg,

1 lb = 0.453592 kg

150 lb = 68 kg

170 lb = 77 kg

120 lb = 54 kg

(i) The person experience a force due to Earth's gravity in the downwards direction. The magnitude of this force is:

F₁ = mg = 68 x 9.8 = 666.4 N

The weight of the person decreases as the elevator is moving upwards. So, the force experienced by the person in this case due to gravity is:

F₂ = 54 x 9.8 = 529.2 N

Applying Newton's force equation;

(F₁ - F₂) = ma

(666.4 - 529.2) = 68 x a

a = 2.02 m/s²

(ii) The weight of the person increases as the elevator is moving downwards. So, the force experienced by the person in this case due to gravity is:

F₂ = 77 x 9.8 = 754.6 N

Applying Newton's force equation;

(F₁ - F₂) = ma

(666.4 - 754.6) = 68 x a

a = -1.30 m/s²

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Answer:

Medium

Explanation:

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4 0
3 years ago
A ball with a mass of 0.25 kg hits a gym ceiling with a force of 78.0 n. what happens next?
QveST [7]
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6 0
3 years ago
What is the approximate de Broglie wavelength of a tennis ball with a mass of 70 g and a velocity of 10 m/s
dybincka [34]

The approximate de Broglie wavelength of a tennis ball is 9.4×10^(-34) m.

What is the de Broglie wavelength:

It is the wavelength that is associated with an object in relation to its momentum and mass is known as de Broglie wavelength.

A particle's de Broglie wavelength is usually inversely proportional to its force.

The formula of de Broglie wavelength:

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here mass of a tennis ball is given

mass, m=70 g = 0.07 kg

ball is moving with velocity

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h is Plank constant,

h=6.63×10^(-34) Js

substituting the values in formula,

λ = 6.63×10^(-34) / ( 0.070*10)

λ = 9.4 ×10^(-34) m

Hence

The approximate de Broglie wavelength of a tennis ball is 9.4×10^(-34) m

Learn more about de Broglie wavelength here:

<u>brainly.com/question/17295250</u>

#SPJ4

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