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Velocity at the bottom of an incline 
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#1
Oct1004, 09:35 PM

P: 23

How can I find the velocity of an object at the bottom of a frictionless incline?
m=108kg Initial Velocity= 4.6m/s Length of ramp=755m Incline=downwards at 19.6 degrees I keep telling myself i'm not unintelligent.... But this keeps replying otherwise 


#2
Oct1004, 09:48 PM

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P: 5,196

Use the given angle and the mass of the object to calculate the component of the object's weight acting parallel to the incline. With this net force acting on it (there is no friction), you know its acceleration from Newton's second law. Kinematics will tell you the final velocity of an object with the given initial velocity traversing this distance at constant acceleration.



#3
Oct1004, 09:50 PM

P: 640

Given: mass, v_{0}, dx, and angle theta, we want to find v. There is a kenematics equation: v^2 = v_{0}^2 + 2*a*dx The only thing you do not know is the acceleration, which you can find from the given quantities. The only thing acting on your object is Gravity. 


#4
Oct1004, 09:57 PM

P: 23

Velocity at the bottom of an incline
and to find the acceleration, is that a=g*SIN(angle)? 


#5
Oct1004, 10:01 PM

P: 640

Acceleration is defined to be a = Sum of all forces / m for constant mass objects. your a = g*SIN(angle) is misleading. It will not work in all cases. 


#6
Oct1004, 10:26 PM

P: 640

Final velocity should be 70.6 m/s down the slope.



#7
Oct1004, 10:52 PM

P: 91

Acceleration down the plane a = gsin(19.6)
distance, s = 755 initial velocity, v' = 4.6 substitute values in V^2 = (V')^2 + 2as v=71 m/s (aprox) 


#8
Oct1004, 11:39 PM

P: 640




#9
Oct1104, 12:44 AM

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P: 3,144

Why not just use energy conservation? The change in kinetic energy in this situation depends only on the net vertical displacement of the object. Remember Galileo! The rest is basic geometry.



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