Answer:
3.924 m/s²
Explanation:
Taking the sum of all upward and downward forces,
EFy = 0;
N1 + N2 - mp.g -mv.g = 0
N1 + N2 = mp.g + mv.g
N1 and N2 are the normal reactions at the wheels, mp is the mass of the driver, mv is the mass of the vehicle and g is the acceleration due to gravity.
Substituting the values in the question,
N1 + N2 = (300+85) x 9.81
N1 + N2 = 3776.85 N
Taking sum of all horizontal forces,
EFx = (mp + mv) x a
μ(N1 + N2) = (mp + mv) x a
μ is the coefficient of friction with a value of 0.4,
Substituting values,
0.4(N1 + N2) = (300 + 85)a
N1 + N2 = 962.5a
Comparing equations,
962.5a = 3776.85
Therefore the acceleration, a = 3.924 m/s²