Part A, B and C Part A Item 2 Caloulate the work done by gravity on the elevator

Question

Part A, B and C

Part A Item 2 Caloulate the work done by gravity on the elevator before it hits the spring. An elevator cable breaks when a 900 kg elevator is 25.0 m above the top of a huge spring (k = 7.00×104 N/m ) at the bottom of the shaft. My Answers Give uo Submit My Answers Give Up Part B Calcuilate the speed of the luvatr wst before striking the spring Calculate the speed of the elevator just before striking the spring m/ s Bubenlt Part C he mount g cmt hers wot a don by both the spring and gravity n amount he sering compesses U hate mat here worh is done by both the spring and gravity) Calculate the amount the sprin ITA

Explanation / Answer

a) Work done by gravity on the elevator before it hits the spring = mgh where m = mass, h = height
mgh = 900 x 9.8 x 25 =220500 J

b) V = 2gh = [(2)(9.8)(25)] = 490 = 22.13 m/s.

c) Work done by both spring and gravity,
220500 = 1/2 kx² + mgx [where k = 8.00e4, x = compression distance]
0 = -220500 + (0.5)(8.00*104)x² + (900)(9.8)x
0 = - 220500 + 8820 x + 4*104 x²
solving for x, positive root = 2.24 m.

so x = 2.24 m

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