A 4.82-kg object is placed upon an inclined plane which has an incline angle of 23.4 degrees. The object slides down the inclined plane with a constant velocity.
how do i find the frictional force?
how do i find the frictional force?
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The information given is:
- mass of the object = m = 4.82kg
- incline angle = θ = 23.4˚
The most crucial piece of information given in the question is the CONSTANT VELOCITY bit. This should straight away tell you that the sum of all forces acting on the object must equal zero because it is not accelerating. There are two forces acting on the object as it is sliding down the inclined plane:
- Gravitational force = W
This is the force of gravity pulling the object down the slope, but we must only consider the component of the force acting down the slope, and by trigonometry we find it is equal to mgsinθ.
- Frictional force = f
All we know is that the frictional force will be acting in the opposite direction to the motion of the object, but since the object is moving at a constant velocity, the magnitude of the frictional force must exactly equal the magnitude of the gravitational force, so they cancel each other out and produce a net force of zero.
Newtons Second law and for a constant velocity states...
Net force = W + f = 0
W + f = 0
so the frictional force will equal...
f = -W
= - (mgsinθ)
= - [4.82*9.81*sin(23.40]
≈ -18.78 N
What this is telling you is that the frictional force has a magnitude of 18.78N acting up the inclined slope.
This answer should be correct, go through it yourself to verify that what I have done is correct though.
- mass of the object = m = 4.82kg
- incline angle = θ = 23.4˚
The most crucial piece of information given in the question is the CONSTANT VELOCITY bit. This should straight away tell you that the sum of all forces acting on the object must equal zero because it is not accelerating. There are two forces acting on the object as it is sliding down the inclined plane:
- Gravitational force = W
This is the force of gravity pulling the object down the slope, but we must only consider the component of the force acting down the slope, and by trigonometry we find it is equal to mgsinθ.
- Frictional force = f
All we know is that the frictional force will be acting in the opposite direction to the motion of the object, but since the object is moving at a constant velocity, the magnitude of the frictional force must exactly equal the magnitude of the gravitational force, so they cancel each other out and produce a net force of zero.
Newtons Second law and for a constant velocity states...
Net force = W + f = 0
W + f = 0
so the frictional force will equal...
f = -W
= - (mgsinθ)
= - [4.82*9.81*sin(23.40]
≈ -18.78 N
What this is telling you is that the frictional force has a magnitude of 18.78N acting up the inclined slope.
This answer should be correct, go through it yourself to verify that what I have done is correct though.
-
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hope this helps! I took physics last year and i wanted to kill myself...I hated it. >:(
hope this helps! I took physics last year and i wanted to kill myself...I hated it. >:(