Kinematics Equation: Solving for t

[LoveBoy]

When we apply this equation ?
v^2-u^2=kt^2/2m

 

[Doc Al]

When we apply this equation ?
v^2-u^2=kt^2/2m

Not sure what that equation is supposed to be. It looks like a mash up of these two:

$x = x_0 + v_0 t + (1/2) a t^2$

$v^2 = v_0^2 + 2 a \Delta x$

 

[LoveBoy]

Not sure what that equation is supposed to be. It looks like a mash up of these two:

$x = x_0 + v_0 t + (1/2) a t^2$

$v^2 = v_0^2 + 2 a \Delta x$

Thanks !