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ksdeponte
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Hello! I am having a lot of trouble with the following problem and would be very grateful for any help that you could offer me!
There is a constant 125 N frictional force that opposes the motion of a soapbox car as it goes down a hill. The mass of the car is 100.0 kg and the angle of the hill is 55degrees, measured from the negative x axis. Its initial speed is 0.0 m/s and the final speed has to be 12.5 m/s in order for the car to make the jump successfully. The goal of the problem is to find the vertical height above the ground needed to have a final velocity of 12.5 m/s.
The problem also gives a hint to solve the problem, determine a way to express the distance the car travels in terms of its vertical height.
F = 125
m = 100.0 kg
theta = 55degrees, measured from the negative x-axis (?), 180degrees for frictional force
vi = 0.0 m/s
vf = 12.5 m/s
delta x = ? m
h = ? m
I've worked on this thing for hours and have no idea what to do.
I know that I will have to use the formula for non-conservative work, and that the final PE and initial KE are not needed. Also, Wnc will have to be in the form of (F cos theta)delta x, and that theta will be 180 since the work done by friction is opposing the car's displacement.
(F cos theta)delta x = KEfinal - PEinitial
= (1/2mvf^2) - (mgh)
But how would you determine delta x in terms of the vertical height, h? I've tried a multitude of things, but never get the right answer.
Thanks in advance for your help!
Katrina DePonte
Homework Statement
There is a constant 125 N frictional force that opposes the motion of a soapbox car as it goes down a hill. The mass of the car is 100.0 kg and the angle of the hill is 55degrees, measured from the negative x axis. Its initial speed is 0.0 m/s and the final speed has to be 12.5 m/s in order for the car to make the jump successfully. The goal of the problem is to find the vertical height above the ground needed to have a final velocity of 12.5 m/s.
The problem also gives a hint to solve the problem, determine a way to express the distance the car travels in terms of its vertical height.
F = 125
m = 100.0 kg
theta = 55degrees, measured from the negative x-axis (?), 180degrees for frictional force
vi = 0.0 m/s
vf = 12.5 m/s
delta x = ? m
h = ? m
Homework Equations
I've worked on this thing for hours and have no idea what to do.
I know that I will have to use the formula for non-conservative work, and that the final PE and initial KE are not needed. Also, Wnc will have to be in the form of (F cos theta)delta x, and that theta will be 180 since the work done by friction is opposing the car's displacement.
(F cos theta)delta x = KEfinal - PEinitial
= (1/2mvf^2) - (mgh)
But how would you determine delta x in terms of the vertical height, h? I've tried a multitude of things, but never get the right answer.
The Attempt at a Solution
Thanks in advance for your help!
Katrina DePonte