Kinematics playgound slide problem

• professor97
In summary, the conversation involves a block placed on a playground slide with an initial speed of 12m/s and an angle of 35 degrees. The coefficient of kinetic friction between the block and the slide is 0.2 and the acceleration due to gravity is 9.8m/s/s. The questions revolve around finding the magnitude of the friction force, the distance the block travels up the slide, and its speed at the bottom. The hint given is to use conservation of energy instead of kinematics equations involving time. It is also suggested to consider the other force acting on the block along the direction of the slope, which is perpendicular to the normal force used to find the friction force.
professor97

Homework Statement

You place a m=2kg block at the bottom of a playground slide and give it a quick kick, giving it an initial speed of vi=12m/s. The slide is inclined at an angle of 35 degrees and the coefficient of kinetic friction between the block and the slide is mu_k=0.2. Use g=9.8m/s/s.
a) What is the magnitude of the friction force on the block while it is moving on the slide? **I found this to (correctly) be 3.2 N
b) Assume the slide is sufficiently long that the block does not go over the top. How far up the slide does the block go?
c) If the block slides back down, what will its speed be at the bottom?

I've been trying to solve this using kinematics equations involving constant acceleration. I know for part (b) that the final velocity is 0 m/s at the top of the ramp. I'm not sure however if the vi needs to be resolved into components, like I had to do to find the frictional force. Also, it was hinted that I might want to avoid finding time, so I've been dealing with the equation vf^2=vi^2+2ad Can the acceleration be found from net force? Would Fnet,x just be 3.2 N? I feel like this problem is a lot simpler than I'm making it out to be. Thanks for any and all help.

If you've been given a hint to avoid finding time (and hence using equations involving time), then you should be thinking "conservation of energy". Remember that friction forces "burn" energy over the distance traveled.

But you could still use basic kinematics. Besides friction, what other force is acting on the block along the direction of the slope? Hint: It's the one perpendicular to the normal force that you used to find the friction force.

1. What is the Kinematics playground slide problem?

The Kinematics playground slide problem is a physics question that involves calculating the acceleration, velocity, and position of an object as it slides down a playground slide. It is a commonly used example to help students understand the principles of kinematics.

2. How do you solve the Kinematics playground slide problem?

To solve the Kinematics playground slide problem, you need to use the basic equations of kinematics: v = u + at, s = ut + 1/2at^2, and v^2 = u^2 + 2as. These equations relate the final velocity (v), initial velocity (u), acceleration (a), displacement (s), and time (t) of an object. By plugging in the given values and solving for the unknown variables, you can find the solution to the problem.

3. What are the key concepts involved in solving the Kinematics playground slide problem?

The key concepts involved in solving the Kinematics playground slide problem include understanding the difference between displacement and distance, the difference between average and instantaneous velocity, and the relationship between acceleration and velocity. It is also important to understand how to use the equations of kinematics and to properly convert units of measurement.

4. Why is the Kinematics playground slide problem important?

The Kinematics playground slide problem is important because it helps to demonstrate the real-world application of kinematics principles. It also helps to develop critical thinking and problem-solving skills, as well as an understanding of how motion can be described and predicted using mathematical equations.

5. What are some tips for solving the Kinematics playground slide problem?

Some tips for solving the Kinematics playground slide problem include carefully reading and understanding the given information, drawing a diagram to visualize the problem, using the correct equations and units, and checking your work for errors. It can also be helpful to break the problem down into smaller, more manageable parts and to practice using the equations of kinematics beforehand.

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