physics
posted by koraile on .
A certain force gives an object of mass m1 an acceleration of 13.0 m/s2 and an object of mass m2 an acceleration of 2.10 m/s2. What acceleration would the force give to an object of mass (a)m2 – m1 and (b)m2 + m1?

(a) 13 = F/m1
2.1 = F/m2
m2/m1 = 13/2.1 = 6.19
F/(m2  m1) = F/[m2(1 (m1/m2)]
= (F/m2)/(1 0.1615) = 2.1/(0.8385)
= 2.5 m/s
(b) F/(m1 + m2) = F/[m2(1 +(m1/m2)]
You finish it. 
i keep on having b) wrong even when replacing

(b) F/(m1 + m2) = F/[m2(1 +(m1/m2)]
= F/m2*[1/(1 + 0.1615)]
= 2.1*/1.1615 = 1.81 m/s^2