BITSAT2019PhysicsMechanical Properties of SolidsActual
A steel wire of cross-sectional area 4 cm 2 has elastic limit of 2 . 2 × 10 8 N m - 2 . The maximum upward acceleration that can be given to a 1000 kg elevator supported by this steel wire if the stress is to exceed one-fourth of the elastic limit is [Take, g = 10 m s - 2 ]
Options
- A10   m   s - 2
- B9   m   s - 2
- C15   m   s - 2
- D12   m   s - 2
Correct answer
D. 12   m   s - 2
Step-by-step solution
Given, Y = 2 . 2 × 10 8   m   s - 2 Area of cross-section of steel wire, A = 4   cm 2 = 4 × 10 - 4   m 2 Mass of elevator, m = 1000   kg The maximum tension in the steel wire that can support elevator is given by T = 1 4 ×  stress  ×  area of cross-section  = 1 4 × 2 . 2 × 10 8 × 4 × 10 - 4 = 2 . 2 × 10 4   N   m - 2 If f be the maximum upward acceleration of the elevator, then T = m   g + f 2 . 2 × 10 4 =