the problem: a plane with a mass of (3.5X10^5)kg is landing. If the speed is 27 m/s and the net braking force is (4.30X10^5) N then a) what is the speed 7.5 sec later? and b) how far has it traveled in this time? this is how i started, because speed is distance/time i felt that it would be better for me to fine the the distance first. so: with the given information i solved for the acceleration using F=MA. the a turned out to be 5.282 m/s^2. from here i used the eq: x=x0+ v0t + .5a(t^2). and this gave me the distance of 53.94 m. then i used this to solve for a which was just 53.94/7.5= 7.192m/s. i am just wonder if my thought process is correct. in the problem it is not stated the the 27 m/s is the initial velocity so i am wondering if it is ok if i used it as such. if anyone could shine some light on the problem or tell if i did it correctly i would appreciated.