1 Newton equals 1 kilogram times
(speed increase of 1 meter per second every second);
1 N = 1 (kg•m)/s2. That is to say, Force equals mass times acceleration.
1 Joule equals 1 Newton times 1 meter; 1 J = 1 N•m. That is to say, Work equals Force driving through (or times) a distance.
1 Watt equals 1 Joule divided by 1 second; 1 W = 1 J/s. That is to say, Power equals Work done divided by time taken to do the work.
If 40 Joules of Work was done in moving the desk 5 meters, then a Force of (40/5) or 8 Newtons was exerted on the desk.
If the Power to move the desk came to 12 Watts, then 40 Joules of Work was done in (40/12) or (10/3) seconds.
Equate Work or Kinetic Energy to 0.5 times mass times (meters per second)2.
Then 40 Joules =
(1/2)mass times (5 meters per (10/3) second)2
or 40 = 0.5 (mass)(1.5 m/s)2.
The mass of the desk would then come to 40÷0.5÷(1.5)2 or 35.55555556 kilograms.
