Answer:
v = 6.32 [m/s]
Explanation:
We know that work in physics is defined as the product of force by distance, in this way we have:
[tex]W=F*d[/tex]
where:
F = force [N]
W = work [J]
d = distance = 4 [m]
[tex]800=F*4\\F=200[N][/tex]
Now we know that by means of Newton's second law which tells us that the total force on a body is equal to the product of mass by acceleration, we can determine the acceleration that occurs.
[tex]F=m*a[/tex]
where:
F = force = 200 [N]
m = mass = 40 [kg]
a = acceleration [m/s²]
[tex]a=F/m\\a=200/40\\a=5[m/s^{2} ][/tex]
Now using this equation of kinematics we can determine the final velocity.
[tex]v_{f}^{2}=v_{o}^{2} +2*a*x[/tex]
where:
vf = final velocity [m/s]
vo = initial velocity = 0 (initially at rest)
a = acceleration = 5 [m/s]
x = distance = 4 [m]
[tex]v_{f}^{2}=0+(2*5*4)\\v_{f}=\sqrt{40}\\v_{f}=6.32[m/s][/tex]
