Johnny stacked 200 cans, each weighing 5 N, on shelves 1 meter high in only 100 seconds. How much power did he use for the task?
m g = 200 * 5 Newtons
work = PE = m g h = 200 * 5 * 1 Joules
work/time=power = 200 * 5 * 1 / 100
Joules/second or Watts
Oso
To find the power used by Johnny for stacking the cans, we need to know the formula for power:
Power = Work / Time
In this case, the work done is the product of force and distance. The force is the weight of the cans, and the distance is the height of the shelves.
First, let's calculate the total weight of the cans:
Weight of one can = 5 N
Number of cans = 200
Total weight of the cans = Weight of one can x Number of cans
Total weight of the cans = 5 N x 200 = 1000 N
Next, we need to calculate the work done by Johnny to lift the cans to the shelves. The work done is the product of force and distance:
Distance = 1 meter
Work = Force x Distance
Work = Total weight of the cans x Distance
Work = 1000 N x 1 meter = 1000 N·m (Newton-meters)
Finally, we can calculate the power using the formula:
Time = 100 seconds
Power = Work / Time
Power = 1000 N·m / 100 seconds
Power = 10 N·m/s (watts)
So, Johnny used 10 watts of power for the task.