Final answer:
The time needed to lift a 70kg mass for 4m with a power output of 1812 watts is approximately 1.51 seconds.
Step-by-step explanation:
To calculate the time needed to lift a 70kg mass for a distance of 4m with a power output of 1812 watts, we need to use the formula:
Power = Work / Time
Rearranging the formula to solve for time, we get:
Time = Work / Power
Given that the work done is equal to the force applied multiplied by the distance moved, which is equal to the weight of the mass multiplied by the distance, we can calculate the work as:
Work = Force x Distance
Using the weight of the mass (Force = mass x gravity), we get:
Work = (mass x gravity) x distance
Plugging in the values, we have:
Work = (70kg x 9.8m/s^2) x 4m = 2744 joules
Finally, we can substitute the values into the time formula to find:
Time = 2744 joules / 1812 watts = 1.51 seconds