contestada

A ball falls straight down through the airunder the influence of gravity. There is aretarding force vector F on the ball with magnitude given byF=b v, wherevis the speed of theball andbis a positive constant. What is the magnitude of the acceleration of the ball at time t/2?

Respuesta :

cjmejiab

So as we know,

[tex]F_1=bv[/tex]

However at the fall, there is two more Force

[tex]F_2 = mg[/tex] (Gravity)

[tex]F_3 = ma[/tex](Net force)

So,

[tex]F_3 = F_2 - F_1[/tex]

[tex]ma = mg -bv[/tex]

[tex]a= g-\frac{bv}{m}[/tex]

For t/2

[tex]a(t/2) = g- \frac{b*\frac{x}{t/2}}{m}[/tex]

[tex]a(t/2) = g-2\frac{bx}{mt}[/tex]