Use the impulse-momentum theorem to find how long the sled takes to travel

[lanky011]

A sled slides along a horizontal surface on which the coefficient of kinetic friction is 0.40. Its velocity at point A is 7.4 m/s and at point B is 3.0 m/s. Use the impulse-momentum theorem to find how long the sled takes to travel from A to B.

(7.4)(.4)=2.96
(3)(.4)=1.2

(2.96)^2+(1.2)^2=10.2016

√10.2016= 3.19

But that's not the right answer

 

[iceblits]

I'm not really sure what you did..but try using the impulse momentum theorem and then remember that impulse=j=F*(delta t)