Initial and Final Energy problem

In summary, the piece of wood will eventually come to rest 6.37m from the initial release point, and the total amount of work done by friction during its motion is 31.45 J.
  • #1
YamiBustamante
17
0

Homework Statement


[/B]
A 2.4 kg piece of wood slides on the surface shown in the figure . The curved sides are perfectly smooth, but the rough horizontal bottom is 31m long and has a kinetic friction coefficient of 0.27 with the wood. The piece of wood starts from rest 4.0m above the rough bottom.

a) Where will this wood eventually come to rest?

b) For the motion from the initial release until the piece of wood comes to rest, what is the total amount of work done by friction?

Homework Equations


E_k = (1/2)mv^2
E_f = mg(u_k)d
E_g = mgh

The Attempt at a Solution



I think I have an idea for part a but I'm not sure. Would this be correct?

Initial Energy = Final Energy
Potential Gravitational Energy = Friction Energy
mgh = Ugdm
(2.4kg)(9.8m/s^2)(4.0m) = 0.27(9.8m/s^2)(2.4kg)d
And then I figured that I would solved for d...
Would that be correct? And for part b would I use the work kinetic energy theorem even though it has friction?
 

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  • #2
I think you got it.
 

1. What is an initial and final energy problem?

An initial and final energy problem refers to a scenario where the initial energy of a system is known, and we want to calculate the final energy of the system after certain changes or processes have occurred.

2. How do you calculate the final energy in an initial and final energy problem?

To calculate the final energy, we use the principle of conservation of energy, which states that energy cannot be created or destroyed, only transferred or converted. This means that the initial energy of the system will be equal to the final energy of the system.

3. What are some examples of initial and final energy problems?

Examples of initial and final energy problems include calculating the final velocity of a moving object, finding the final potential energy of a lifted object, or determining the final kinetic energy of an object that undergoes a change in speed.

4. What is the formula for calculating the final energy in an initial and final energy problem?

The formula for calculating the final energy is: final energy = initial energy + work done + heat added or subtracted. This formula takes into account any changes in the energy due to work being done on the system or heat being added or removed from the system.

5. What are the units of energy used in initial and final energy problems?

The units of energy used in initial and final energy problems can vary depending on the type of energy being measured. Some common units include Joules (J), foot-pounds (ft-lb), and calories (cal). It is important to ensure that all values used in the calculation have the same units for accurate results.

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