Posted by David on .
Calculate the total constant force needed to accelerate a vehicle with mass 1400kg and tractive resistance of 320N from 19km/h to 95km/h over a distance of 0.8km on a horizontal plane.show working?

fundamentals 
herp_derp,
ah...DANNY..we meet again...
not sure if this is right but i'll take a shot at it...
1. convert all the info into MKS units (MKS = meters, kilograms, seconds)
19 km/hr = 5.277 m/s
95 km/hr = 26.388 m/s
0.8 km = 800 m
2. start with this equation:
vf^2 = vi^2 + 2ad
then, solve for "a"
a = (vf^2  vi^2)/(2d)
plug in the numbers...
((26.388 m/s)^2  (5.277 m/s)^2)/(2 x 800 m) = 0.4178 m/s^2
3. then we take care of those vectors...
Fo  Fe = Fc
ma  Fe = Fc
(1400 kg)(0.4178 m/s^2)  (320 N) = 264.92 N

remember DANNY.....HERP THE DERP!!!