Example of Labor and Conservation Laws

The mechanical work is equal to the product of the component of the force in the direction of motion of the body times the distance the body travels. It is a scalar quantity.

W = Fd or W = (Fcos0) d
W = work
F = force
d = distance

Work units

Kpm = kilopondimeter
J = joule
J = Nm = 0.102 Kpm
1Kpm = 9.81 J
Nm = newton x meter

Example of conservation laws:

Example of mechanical work:

Calculate the work done by a body moving with a force of 18N, in a distance of 10 meters.

W =?
F = 18 N
d = 10m
W = Fd
W = (18N) (10m) = 180J

Calculate the work of a 50 N force that is applied at an angle of 30 ° with the horizontal that travels 25 m.

W =?
F = 50N cos 30 °
d = 25m
W = (Fcos0) d
W = (50N) (0.866) 25 m)
W = 1082.5 J

Power: It is the quotient of dividing the work done by a force by the time spent doing it.

P = Watt
W = J
t = s
v? m / s
P = W / t = Fd / t = Fv

Power example:

Calculate the power generated by the work done by a force of 80N in 30m, during 50s.

P =?
W =?
F = 80 N
t = 50 s
d = 30 m
P = Fd / t = (80 N) (30 m) / 50s = 48 W
W = Fd = (80 N) (30 m) = 2400 J

Energy: It is the ability of a body to do work. Its units are:

1 Joule = kg m²/ s² = 0.238 cal
1 cal 4.186 J
I Btu = 60.2 J