Q1. Assume a small child rolls off a bed that is 0.4 m above floor. If the floor is hardwood, the child's head is brought to rest in approximately 2 mm. If the floor is carpeted, this stopping distance is increased to about 1cm. computed the magnitude and duration of the deceleration in both cases, to determine the risk of injury. Presume the child remains horizontal during the fall to the floor. Note that a more complicated fall could result in a head velocity greater or less than the speed you calculate.

Q2. A heavy crate rests on the bed of a flatbed truck. When truck accelerates, the crate remains where it is on the truck, so it, too, accelerates. What force causes the crate to accelerate? Does force change if the truck is on an incline or on level ground? If it changes, what is difference?