Easy question Newtons 1st law of motion, applying force to a hockey puck

[offbeatjumi]

** sorry. this would be Newtons 2nd law of motion. oops.

Homework Statement

Hockey puck with mass 0.160kg at rest at x=0 and t=0 on horizontal frictionless surface. hockey player applies force of 0.250 N until t = 2.00s. ... ... if the same force is applied again at t = 5.00 s what is the position and speed of the puck at t = 7.00s?

Homework Equations

x(final) = x(initial)+v(initial)t+(1/2)a(t^2)
v(final) = v(initial)+at

The Attempt at a Solution

at t = 2 seconds, the puck is at x = 3.125m and the velocity is 3.125m/s. the acceleration (from F = ma) is 1.5625 m/s^2.
how do I incorportate reapplying the force? i imagine since the surface is frictionless and the acceleration is constant that the puck keeps increasing in velocity right?

 

[tiny-tim]

Hi offbeatjumi!

(try using the X² tag just above the Reply box )

how do I incorportate reapplying the force? i imagine since the surface is frictionless and the acceleration is constant that the puck keeps increasing in velocity right?

I'm not sure what you're asking.

The puck will have zero acceleration, and therefore the same velocity, until the force is reapplied.

So find the new x at the end of that constant velocity, and use that as the initial x in the same equation as before.

 

[offbeatjumi]

im sorry i worded that wierdly

this is essentially the question: if the same force is applied again at t = 5.00 s what is the position and speed of the puck at t = 7.00s?

but what you said helps, ill try it