A 50kg man is standing on a spring in an elevator thats accelerating upward. How much is the spring compressed

Question

A 50 kg student is standing atop a spring in an elevator that is accelerating upward at 3.6 m/s2. The spring constant is 2300 N/m. By how much is the spring compressed?

Answer 1

w = mg =50*9.8 = 490 N  is his weight

F = ma = 50*3.6 = 180 N due to acceleration

Total force = 490 +180 = 690 N

Now the spring compresses according to

F = kx

x = F/k = 690/2300 = 0.3 m = 30cm