You are pulling your little sister on her sled across an icy (frictionless) surface. When you exert a constant horizontal force of 113 N, the sled has an acceleration of 1.3 m/s2 If the sled has a mass of 6.6 kg, what is the mass of your little sister?

Answer 1

As you know, Bob, F=ma

113 = (6.6+s)(1.3)
113 = 8.58 + 1.3s
1.3s = 104.42
s = 80.32kg

Looks like "little" sister needs to do some walking!