Using kinetic and dynamic principles to determine unknown parameters

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To determine how far a 700 kg motor vehicle traveling at 36 km/h will roll to a stop after being taken out of gear, the kinetic energy must first be calculated. The rolling resistance is given as 155 N, and the kinetic coefficient of friction is 0.023. Applying Newton's laws, the forces in the vertical direction balance out, while the horizontal forces lead to acceleration. By using the equations of motion related to constant acceleration, the distance traveled can be derived. This approach effectively combines kinetic and dynamic principles to solve for the unknown parameters.
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A motor vehicle has a mass of 700Kg and is traveling at 36 km/h on a level road; it is taken out of gear and allowed to roll to a stop.

The first part of the question asks me to work out the kinetic energy which I've done and then the next part asks how far will it travel if the rolling resistance between the road and the wheels is 155N? The kinetic coefficient of friction is 0.023.

I really need help with this, I'm really struggling!

Thanks in advance!
 
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Start with Newton's laws. Write down the equations of motion that will relate all your parameters
 
The Captain is right on the mark Drizzle,

Keep in mind two things:

1.) The forces in the vertical direction are equal because the car is not bouncing up or down, \sum F_y = 0

2.) There is an acceleration in the x-direction, \sum F_x = ma.

After that you have a simple constant acceleration kinematic situation, find the right formula and solve for the distance.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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