Respuesta :
Answer:
Explanation:
PART A
From Newtons second law:
[tex] F=ma\\a=\frac{F}{m}\\\frac{dv}{dt}=\frac{F}{m}\\\\(\frac{dv}{ds}\times\frac{ds}{dt})=\frac{F}{m}\\\\v\frac{dv}{ds}=\frac{F}{m}\\vdv=\frac{F}{m}ds[/tex]
Integrating above expression by applying limits:
[tex]\int\limits^{vf}_{v_{i}} {vdv} =\frac{F}{m}\int\limits^5_0ds[/tex]
Here Distance =D
[tex]\frac{v^2_f-v^2_i}{2}=\frac{FD}{m}[/tex]
The final speed of the particle after travelling distance D
[tex]v_f=\sqrt{v^2_i+\frac{2FD}{m}}[/tex]
PART B
The Kinetic energy of the particle of mass M is,
[tex]K_1=\frac{1}{2}Mv^2[/tex]
For [tex]M=3M\\K_2=\frac{1}{2}(3M)v^2=3(K_1)[/tex]
The kinetic energy increases by factor 3
The workdone depends on the factor and displacement of the body. Therefore, workdone increases by factor 1.
PART C
Final velocity is,
[tex]v_f=\sqrt{v^2_i+\frac{2FD}{m}}[/tex]
Here,[tex]\frac{F}{m}[/tex] represents the acceleration [tex]a[/tex]
For[tex]m=3M\\\\a=\frac{F}{2M}[/tex]
In this case acceleration is decreased so, velocity also decreases.
PART D
Initial kinetic energy is
[tex]K_1=\frac{1}{2}Mv^2[/tex]
Here [tex]v=3v\\\\K_1=\frac{1}{2}M(2v)^2\\\\=[tex]K_1=9(\frac{1}{2}M(v)^2)[/tex]
Kinetic energy increases by factor of 9. workdone remains same even as velocity increases. Therefore, workdone increases by factor 1
PART E
The final speed of the particle is
[tex]v^2_{f'}=v^2_i+\frac{2FD}{m}[/tex]....(1)
The final speed of the particle with speed [tex]3v_i[/tex] is,
[tex]v^2_{f'}=9v^2_i+\frac{2FD}{m}[/tex]....(2)
substract two equations:
[tex]v_{f'}-v_f=\frac{8v_i^2}{(v_{f'}+v_f)}\\\\=\frac{8v_i}{\sqrt{9}+\sqrt{1}}\\=2v_i[/tex]
Thus the particle changes in speed over distance D and will be less with an initial speed equal to [tex]v_i[/tex]