A machine can produce a larger force than you apply, but it can never do more work than you put into it. The ratio of work output to work input is called the efficiency of the machine. A box weighing 240N is pulled up an inclined plane that is 2.0m long. The force required is 160 newtons. If the height of the inclined plane is 1.0m, calculate the work input and the work output.
what is the effort force?
what is the effort distance?
what is the resistance force?
what is the resistance distance?
2007-02-24 09:03:09 · 1 answers · asked by daddysgurl902000 1 in Education & Reference ➔ Homework Help
Effort force = weight * sin θ
To find θ:
opposite / hypotenuse = 1/2
sin 30 = .5, so θ = 30 degrees
Resistance force is the component of the box's weight that goes back down the ramp.
Fr = weight * sin θ = 240 N * .5 = 120N
Resistance distance = 2m (up the ramp)
Effort Force = 160N (as given)
Effort distance = 2m (again, up the ramp.
Work input = 160N * 2m = 320J
Work output = Fr * d = 120N * 2m = 240J, which also equals the work needed to just lift the box (weight * height).
Efficiency = work output / work input = 240 / 320 = 75%
However, the reduction in force is significant: the force required to lift the box was 240N (the weight) - you use 1/3rd less force to achieve the same result.
2007-02-26 05:55:23 · answer #1 · answered by ³√carthagebrujah 6 · 0⤊ 0⤋