While an elevator of mass 2490 kg moves upward, the tension in the cable is 34.5 kN

a) What is the acceleration of the elevator?

b) If at some point in the motion the velocity of the elevator is 1.27 m/s upward, what is the elevator's velocity 3.97 seconds later?

a) write newton's second law:

T - mg = ma

34500N - 2490kg*9.8m/s/s = 2490 a

a=4.05m/s/s

b) v(t)=v0+ at = 1.27m/s + 4.05m/s/s*3.97s = 17.4m/s

From T = m(g+a), we have a = T/m - g

a) a = 4.055 m/s²

b) V = Vi + a*t = 1.27 + 4.055*3.97 = 17.37 m/s