physics
posted by shelly on .
1) a loaded cart with a mass of 96 kg sits at reat atop a 40 degree inclined plane that measures 20.5m long. accidentally the cart starts so to roll down the inclined plane with a frictional force of 5550N working against it for the intire 20.5m. deteremine the speed at the bottom og the incline plane.
2) a 1,420kg boulder at rest, begins to roll down a 52m long hillside. while rolling, the ground causes a frictional force of 12,040N. the boulder arrives at the bottom of the hillside with a speed of 19.5m/s. determine the boulder's original height.

1. Wc = 96kg * 9.8N/kg = 940.8N @ 40deg = Weight of cart.
Fp = 940.8sin40 = 604.7N = Force parallel to the plane.
Fv = 940.8cos40 = 720.7n = Force perpendicular to the plane.
Ff = 555N = Force due to friction.
Fn = Fp  Ff = 604.7  555 = 49.7N =
Net force.
a = Fn/m = 49.7 / 96 = 0.518m/s^2.
Vf^2 = Vo^2 + 2ad
Vf^2 = 0 + 2*0.518*21.5 = 22.27,
Vf=4.7m/s = Speed at bottom of incline.