Question

a net force of 3000 N is accelerating a 1200kg elevator upward. If the elevator starts from rest, how long will it take to travel up 15m?

Answer 1

Answer:

3.46 s

Explanation:

First of all, we can calculate the acceleration of the elevator by using Newton's second law:

$F=ma\\a=\frac{F}{m}=\frac{3000 N}{1200 kg}=2.5 m/s^2$

and the acceleration has the same direction of the net force (upward).

Now we can calculate the time takes for the elevator to cover a distance of S=15 m by using the following SUVAT equation:

$S=\frac{1}{2}at^2$

where a is the acceleration and t the time. Re-arranging the equation, we find

$t=\sqrt{\frac{2S}{a}}=\sqrt{\frac{2(15 m)}{2.5 m/s^2}}=3.46 s$