Question

5. What is the tension of the cable of a 2000 kg elevator in City Center if it a) is accelerating up at a rate of 1.5 m/s2? (2 marks) b) is accelerating down at a rate of 1.5 m/s?? (2 marks) Moving upat a constant velocity of 70 m/s (2 marko) d) Moving down with a constant velocity of 5 m/s (2 marks) 6. The picture below is an example of an Atwood machine, m-3.55 kg, m,-2.77 kg Find the a) acceleration of the system. (3 marks) mig m b) tension of the rope. (2 marks)

Answer 1

Tension in the cable is given by

T = m( g + a)

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a) T = 2000*(9.8+ 1.5) = 22600 N

b) T = 2000 (9.8 - 1.5) = 16600 N

c) T = 2000 (9.8 +0) = 19600 N

d) T = 2000 (9.8 +0) = 19600 N

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6.

Acceleration of this Atwoods machine is given by

a= g ( m1 - m2) /(m1 + m2)

a = 9.8 ( 3.55 - 2.77)(3.5 + 2.77) = 1.21 m/s^2

Tension is given by

T = 2.77 ( 9.8 + 1.21) = 30.5 N

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