# There are a few problems listed, two of them I hav…

### Question Description:

20.50

There are a few problems listed, two of them I have the answer! #1. A woman is pushing a box along the ground. She is exerting a horizontal force of 156 N on the box. The box has a mass of 84.0 kg, and has an opposing horizontal frictional force of 135 N. What is the coefficient of kinetic friction between the box and the ground? (The answer should be 0.164) #2.A rocket skateboard of mass 3.00 kg has an initial velocity of (5.00, 2.50) m/s. A net force of (3.40, 2.67) N is applied to it for 10.0 s. At the end of this time, what is its velocity? Answer: (___,___) m/s #3. A ball moving through a special sticky fluid encounters a drag force whose magnitude, in newtons, is proportional to the fourth power of its velocity, expressed in meters per second. That is, FD = Av^4. (a) What are the units of the coefficient “A”? Express your answer using the SI base units of kilograms, meters, and seconds. (b) If a ball of mass m is dropped from rest into a deep container of the sticky fluid, find an expression for the terminal velocity that it reaches. (The answer should be: (a) kg∙s^2/m^3 (b) Submit answer on paper.)