2006-08-18 05:43:37 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
Because motion is impeded by friction, and friction acts at a right angle to the surface (i.e., directly into the surface). So the angle of friction changes as the slope angle increased, but gravity is always acting downward.
The ability of friction to impede motion is based upon the cosine of the angle between the direction of friction and the direction of gravity. As that angle goes to 90°, the cosine goes to 0, so friction doesn't work.
Or think of it visually. If the slope is 0°, friction will hold the object in place. If the slope is 90°, friction cannot stop the object at all. As the slope moves from 0° to 90°, friction becomes less and less effective.
2006-08-18 06:08:44 · answer #1 · answered by TychaBrahe 7 · 1⤊ 0⤋
The angle of repose is the maximum angle (or max point of friction) that can be achieved w/o sliding. This is the point or angle that unconsolidated materials on a slope will achieve before falling. (from a geological perspective)
When the force of gravity overcomes the frictional forces between the block (or in the case of mass wasting, unconsolidated material) & the incline plane, movement will occur.
As you increase the angle of the inclined plane, the force of gravity will start to exceed the frictional forces b/t the block & the plane. Gravity "takes over" if you will.
The angle of repose will change according to the types of materials being used b/c the coefficient of friction for materials is different. (i.e. wood & metal- metal has a lower c of friction.)
2006-08-18 21:28:44 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The vertical force of gravity can pull it down more easily if the inclined plane is steep. Low angle inclined planes require more horizontal force.
2006-08-18 12:51:41 · answer #3 · answered by scuderia 2 · 1⤊ 0⤋
The center of gravity of the block is changed as the angle of repose is increased. It is sliding because it is trying to tip over and can't.
2006-08-18 14:00:56 · answer #4 · answered by 8 In the corner 6 · 0⤊ 1⤋
as the angle increases the potential energy increases due to the reduction of the impact of x-axis forces and the increase of the impact of the y-axis forces (gravity)
2006-08-18 13:04:44 · answer #5 · answered by Texan Pete 3 · 0⤊ 0⤋
X axis forces decrease... more gravitational forces helping it and less static frictional forces
2006-08-18 12:52:29 · answer #6 · answered by MadMaxx 5 · 1⤊ 0⤋
gravity :)
2006-08-18 12:51:53 · answer #7 · answered by sponggie 3 · 1⤊ 0⤋