8. Consider a large truck carrying a heavy load, such as steel beams. A significant hazard for
the driver is that the load may slide forward, crushing the cab, if the truck stops suddenly in
an accident or even in braking. Assume, for example, a 10 000-kg load sits on the flatbed of a
20 000-kg truck moving at 12.0 m/s. Assume the load is not tied down to the truck and has a
coefficient of static friction of 0.500 with the truck bed. (a) Calculate the minimum stopping
distance for which the load will not slide forward relative to the truck. (b) Is any piece of data
unnecessary for the solution?
9. As a fish jumps vertically out of the water, assume that only two significant forces act on it: an
upward force F exerted by the tail fin and the downward force due to gravity. A record
Chinook salmon has a length of 1.50 m and a mass of 61.0 kg. If this fish is moving upward
at 3.00 m/s as its head first breaks the surface and has an upward speed of 6.00 m/s after
two-thirds of its length has left the surface, assume constant acceleration and determine (a)
the salmon's acceleration and (b) the magnitude of the force F during this interval.
