Horizontal Force - Friction Problem

[tylenolman]

http://img151.imageshack.us/img151/8411/physicsks7.jpg

http://www.glpics.com/cristianb/Pics/penguin%20physics.JPG

How would I go about solving this problem?
Do you just ignore the sled and snow friction?
Any help would be great.

 

[Delzac]

You can't ignore the sled and snow friction. Please that note that the force you exert of the sled + penguin is not the force experience by the penguin, since part of the force is " filtered" off by friction between the snow and sled.

This should be enough to send you in the right direction :)

Off Topic : Cute Penguin you have BTW

 

[kyle8921]

I would approach this problem by first identifying the known and unknown variables. From the given information, we know the mass of the penguin (m = 20 kg), the angle of the slope (θ = 30°), and the coefficient of kinetic friction (μk = 0.2). The unknown variable is the horizontal force (F) required to move the penguin at a constant velocity.

To solve for F, we can use Newton's second law which states that the net force (Fnet) acting on an object is equal to its mass (m) multiplied by its acceleration (a). In this case, the penguin is moving at a constant velocity, so its acceleration is 0. Therefore, Fnet = 0 and we can set up the following equation:

Fnet = F - μkmgcosθ = 0

Where g is the acceleration due to gravity (9.8 m/s^2).

Solving for F, we get:

F = μkmgcosθ = (0.2)(20 kg)(9.8 m/s^2)cos(30°) = 34.13 N

So the horizontal force required to move the penguin at a constant velocity is approximately 34.13 N.

To answer the second question, we cannot ignore the sled and snow friction as they are the forces acting against the horizontal force we calculated. Without considering these forces, we would not be able to accurately determine the required force to move the penguin. Therefore, it is important to take all relevant factors into account when solving a physics problem.

I hope this helps and provides a clear understanding of how to approach and solve this problem. If you have any further questions, please do not hesitate to ask.