Answer:
Step-by-step explanation:
To solve this problem, we need to use the equation for work:
Work = Force × Distance
where Force is the weight of the load (mass × acceleration due to gravity).
Given that the load is 100 kilograms, its weight is:
Force = mass × acceleration due to gravity = 100 kg × 9.81 m/s^2 = 981 N
The work done in lifting the load a distance of 20 meters is:
Work = Force × Distance = 981 N × 20 m = 19,620 J
The time taken to do this work depends on the power output of the motor, which is given as 3.0 kilowatts (3,000 watts).
Power = Work / Time
Rearranging this equation to solve for time, we get:
Time = Work / Power
Substituting the values we have, we get:
Time = 19,620 J / 3,000 W
Time = 6.54 seconds (rounded to two decimal places)
Therefore, it will take the motor approximately 6.54 seconds to lift the 100 kilogram load of bricks a distance of 20 meters at maximum power.