Final answer:
The time needed to lift the 70 kg person a distance of 4 meters is approximately 1.59 seconds.
Step-by-step explanation:
To find the time needed to lift the 70 kg person a distance of 4 meters, we can use the power output of the elevator motor. Power is defined as the work done per unit time. In this case, the power is given as 1,719 watts. Since the work done is equal to the force multiplied by the distance, and power is equal to work divided by time, we can rearrange the equation to find time as:
Time = Work / Power
Work = Force x Distance
Plugging in the values, we get:
Work = (70 kg x 9.8 m/s^2) x 4 m = 2744 J
Time = 2744 J / 1719 W = 1.59 seconds.