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schepotkina [342]
3 years ago
10

An object is suspended by a string from the ceiling of an elevator. If the tension in the string is equal to 25 N at an instant

when the elevator is accelerating downward at a rate of 2.0 , what is the mass of the suspended object
Physics
1 answer:
Phantasy [73]3 years ago
4 0

By Newton's second law, the net force on the object is

∑ <em>F</em> = <em>T</em> - <em>mg</em> = - <em>ma</em>

where

• <em>T</em> = 25 N, the tension in the string

• <em>m</em> is the mass of the object

• <em>g</em> = 9.8 m/s², the acceleration due to gravity

• <em>a</em> = 2.0 m/s², the acceleration of the elevator-object system

Solve for <em>m</em> :

25 N - <em>m</em> (9.8 m/s²) = - <em>m</em> (2.0 m/s²)

==>   <em>m</em> = (25 N) / (9.8 m/s² - 2.0 m/s²) ≈ 3.2 kg

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b. Time, t = 7.87 seconds.

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Given the following data;

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858.49 = 210.25 + 344a

344a = 858.49 - 210.25

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Acceleration, a = 1.88 m/s²

b. To find the time;

We would use the first equation of motion;

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1.88t = 29.3 - 14.5

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Time, t = 14.8/1.88

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Four fundamental forces are gravitational, electromagnetic, strong, and weak.

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