Work and kinetic energy?

Question

A 21.6 Kg box initially at rest is pushed 6.63 m along a rough, horizontal floor with a constant applied horizontal force of 101.86 N. The acceleration of gravity is 9.8 m/s^2. The coefficient of friction between box and floor is 0.399.

1.) Find the work done by the applied. Answer in units J
2.) Find the work done by the friction. Answer in units of J
3.) Find the change in Kinetic energy of the box. Answer in J
4.) Find the final speed of the box. Answer in units if m/s

Yes. I did read my physics book...didn't really help.
No. I don't want the answers. All i want is an equation or some type of help.

Answer 1

Work W is a product of force F applied along the displacement s. We have
1. W=Fs
F= 101.86N ; s=6.63 m
W1= 101.86 x 6.63=675 J

2. W=fs
f= umg
W2= 0.399 x 21.6 x 9.8 x 6.63 = 560 J

3. Change from where to where? Assuming from rest and past 6.63m...The kinetic energy Ke is the difference between energies spent on moving the block W1 and energy used on motion against friction. from law of conservation of energy
W1 - W2 - Ke=0

Ke= W1- W2=675 - 560 = 115J

4.Ke = 0.5mv^2 then
v=sqrt(2(W1-W2)/m)
v=sqrt(2(115)/21.6)
v=3.26 m/s

I hope it helps.

Answer 2

certainly thermal power is kinetic temperature is the diploma of the essential kinetic power of the debris in a pattern yet there is likewise skill power this is power linked with place or some condition an merchandise sitting on a table has skill power with admire to the floor yet there is not any action if the object falls, then that skill power is converted to kinetic chemical bonds have skill power this is on occasion converted to kinetic (in general interior the form of thermal power) as while a gasoline inclusive of methane is burned the debris interior the nucleus of an atom have skill power that is converted to kinetic (many times thermal) power while the debris are rearranged as in fission or fusion of nuclei