Question

An elevator of mass 400 kg is moving upwards and the tension in the supporting cable is 40,000 N. Find the upward acceleration . How far does it rise in a time of 10 s starting from rest(g=9.8 m/$s^2$)

Answer 1

We have,

$mass=400kg,T=40,000N,t=10s$

So,

$F=ma$

Let upward acceleration is a

$a=\frac{f}{m}$

$a=\frac{40000}{400}$

$=100m/s^2$

Now,

$2as=v^2-u^2$

S is height

$v=u+at$

$v=at$ Since $u=0$

$v=1000m/s$

So,

$2as=v^2$

$=\frac{1000\times 1000}{2\times 100}$

$=5000m$