A child boards a bus for summer camp. His mom is waiting next to the bus. The bus begins
moving 3 m/s east with respect to the ground. The child is walking 0.5 m/s west towards the back
of the bus with respect to the bus. The mother begins running 1 m/s east with respect to the
ground, chasing after the bus and thoroughly humiliating her child. What is the child's velocity

a) relative to the ground?

b) relative to the mother?