posted by mj on .
To show your friends how strong you are, you start pushing a big container with mass 50 kg along a long, flat highway. While you are pushing the container in a horizontal direction with an average force 350 N, it moves with acceleration 1 m/s/s. After 5 seconds of pushing you give up and stop pushing. Find values of as many variables or physical quantities as you can.
Fn = ma = 50 * 1`= 50N. = Net force.
Fap - Fk = Fn,
350 - Fk = 50,
Fk = 350 - 50 = 300N = Force of kinetic friction.
Fap = Force applied.
d = Vo*t + 0.5a*t^2,
d = 0 + 0.5*%^2 = 12.5m.
Work = Fd = 350 * 12.5 = 4375 Joules.
Power = F*d/t=4375/5= 875J/s=875Watts.
Correction: d = 0 + 0.5*5^2 = 12.5m.