Question

An elevator rises steadily up a skyscraper. After 4 s it is 33 m above the ground, 2 s later it is 47 m above the ground. Which equation models its position, y, with respect to time, x?

Answer 1

The 2nd motion eqn.

S = ut + 1/2gt²

where, u is the initial speed of the elevator

S = position

and t = x

y = ux + 1/2gx²

y = 1/2gx² + ux

since the elevator started at 0 as initial speed(that is at rest)

y = 1/2gx² + 0

y = 1/2gx² is the eqn