I have a question about Kinetic and Potential Energies.

[Alhussaini]

Question: The top of a chute whose length is 12 meters is 3 meters vertically above its lowest point. A parcel of mass 1.6 Kilogram slides from rest from the top of the chute and reaches the lowest point with a speed of 5 meters per second. Calculate, for the the parcel:

(A) The gain in Kinetic Energy.
(B) The loss in Potential energy.
(C) The Work done in overcoming the frictional resistance.
(D) The average value of this resistance (force of friction).

Homework Statement

Homework Equations

KE and PE equations obviously.

The Attempt at a Solution

No idea. please everyone have a go at this.

 

[ap123]

Hello Alhussaini

What are your ideas on this?

 

[Alhussaini]

Hello Alhussaini

What are your ideas on this?

sorry i have no idea how to solve this, as i literally can't understand the English in this one.
please have a go at it and see if you can solve it. Your help is much appreciated! seriously it is !

 

[Doc Al]

Treat the "chute" as an inclined plane which the parcel slides down.

 

[Nickie]

Hello,

Thank you for your question. To answer your question, we must first understand the concepts of kinetic and potential energies. Kinetic energy is the energy an object possesses due to its motion, while potential energy is the energy an object has due to its position or configuration.

(A) To calculate the gain in kinetic energy, we can use the equation KE = 1/2mv^2, where m is the mass of the parcel and v is its final velocity. In this case, m = 1.6 kg and v = 5 m/s. Plugging these values into the equation, we get KE = 1/2(1.6 kg)(5 m/s)^2 = 20 Joules.

(B) To calculate the loss in potential energy, we can use the equation PE = mgh, where m is the mass of the parcel, g is the acceleration due to gravity (9.8 m/s^2), and h is the height difference between the top and bottom of the chute. In this case, m = 1.6 kg and h = 3 m. Plugging these values into the equation, we get PE = (1.6 kg)(9.8 m/s^2)(3 m) = 47.04 Joules.

(C) The work done in overcoming frictional resistance can be calculated using the equation W = Fd, where F is the force of friction and d is the distance traveled. Since the parcel is sliding from rest, the initial velocity is 0, so the work done by friction is equal to the change in kinetic energy. Therefore, the work done in overcoming frictional resistance is also 20 Joules.

(D) To find the average value of the frictional resistance, we can use the equation F = ma, where m is the mass of the parcel and a is its acceleration. Since the parcel is sliding at a constant speed, its acceleration is 0. Therefore, the average value of the resistance is also 0.

I hope this helps answer your question. Please let me know if you have any further questions or need clarification.