Final answer:
Sam's top speed is found by calculating the net force acting on him (the thrust minus the force of friction) and using Newton's second law to find his acceleration. His velocity over the 11 seconds of thrust is then determined using the kinematic equation for constant acceleration.
Step-by-step explanation:
To determine Sam's top speed on his jet-powered skis, we must consider the forces acting on him as he accelerates on the snow. The thrust of the skis provides a forward force while friction provides a force opposing motion. We are given that the thrust (Fthrust) is 190 N and the coefficient of kinetic friction (μk) is 0.1.
The force of friction (Ffriction) can be calculated using the equation Ffriction = μk × normal force (N). Since the snow is level, the normal force is equal to the weight of Sam (mass × acceleration due to gravity). So, Ffriction = 0.1 × 71 kg × 9.8 m/s2.
The net force (Fnet) acting on Sam is the thrust minus the force of friction. Fnet = Fthrust - Ffriction. We use Newton's second law to calculate the acceleration (a) that Sam experiences, with Fnet = mass × acceleration.
Sam's acceleration is then used to find his velocity after the 11 seconds of fuel burn using the equation v = u + at, where u is the initial velocity (which is 0 m/s since he starts from rest), a is the acceleration, and t is the time.
Therefore, Sam's top speed (v) can be found by inserting the values into the equation and calculating the result.