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4. A 65 kg woman is inside an elevator. Calculate her apparent weight (Normal Force) for the following cases:

a. The elevator moves at constant speed of 10 m/s downward (2 pts)
b. The elevator accelerates upward at a constant rate of 2.4 m/s2 (2 pts)
c. If the scale read 450 N. Find the magnitude and direction of the elevator’s acceleration. (3 pts)

Respuesta :

Answer:

Explanation:

a ) Let her apparent weight be W₁

Net force on her = W₁ - mg

acceleration a = 0

W₁ - mg  = 0

W₁   =   mg = 65 x 9.8 = 637 N  

b )

a = 2.4 m /s²

W₁ - mg  = ma

W₁  = m(g + a )

= 65 x ( 9.8 + 2.4 )

= 793 N

c )

W₁ = 450 N

a = ?

W₁ - mg  = ma

450 - 65 x 9.8 = 65 x a

65 a = - 187

a = - 2.87 m /s²

acceleration is negative therefore , it must be downwards   .

raphealnwobi

The elevator was accelerating downward at a constant rate of -3.1 m/s²

Let the acceleration due to gravity (g) = 10 m/s²

a) When moving at constant speed of 10 m/s downward:

Net force = mass * g = 65 kg * 10 m/s² = 650N

b) Net force = Mass * g + mass * acceleration

Net force = (65 * 10) + (65 * 2.4) = 806 N

c) Net force = Mass * g + mass * acceleration

450 = 65 * 10 + (65*a)

65a = -200

a = -3.1 m/s²

The elevator was accelerating downward at a constant rate of -3.1 m/s²

Find out more at: https://brainly.com/question/18376691

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