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A skydiver will reach a terminal velocity when the air drag equals their weight. For a skydiver with high speed and a large body, turbulence is a factor. The drag force then is approximately proportional to the square of the velocity. Taking the drag force to be
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- (a) Calculate the retarding force due to viscosity of the air layer between a cart and a level air track given the following information: air temperature is 20°C, the cart is moving at 0.400 m/s, surface area is 2.50102 m2, ad thickness of air layer is 6.00105 m. (b) What is the ration of this force to the weight of the 0.300-kg cart?arrow_forwardA skydiver will reach a terminal velocity when the air drag equals his or her weight. For a skydiver with a large body, turbulence is a factor at high speeds. The drag force then is approximately proportional to the square of the velocity. Taking the drag force to be FD =1/2 ρAv2, and setting this equal to the skydiver’s weight, find the terminal speed for a person falling “spread eagle.”arrow_forwardThe drag force, D, on a plate moving with a velocity of (40.0 ± 0.2) km/h through air of density p = ( 1.200 ±0.010) kg/m3, with a surface area of (100.00 ± 0.5mm) x (30.00 ± 0.05cm) is given by D = Cd p AV² where Ca= 2.1 is a non-dimensional constant. What is the drag force D? 30.00 cm 100.00mm O D = 9.33 ± 0.233 N D = 8.9±0.2kg D =0.89±0.22 N D = 9.33 ± 2.33 x 101 N D = 9.3 ± 0.2 Narrow_forward
- What is his terminal speed if he falls feet first? Use ρ = 1.2 kg/m3 for the density of air at room temp.arrow_forwardBy comparing the surface area of a sphere with its volume and assuming that air resistance is proportional to the square of velocity, it is possible to make a heuristic argument to support the following premise: For similarly shaped objects, terminal velocity varies in proportion to the square root of the length. Expressed in a formula, this is T = kL0.5, where L is length, T is terminal velocity, and k is a constant that depends on the shape, among other things. This relation can be used to help explain why small mammals easily survive falls that would seriously injure or kill a human. (Round your answers to two decimal places.) (a) A 5-foot woman is 20 times as long as a 3-inch mouse (neglecting the tail). How does the terminal velocity of a woman compare with that of a mouse? The terminal velocity of the woman is ________ times that of the mouse? (b) If the 5-foot woman has a terminal velocity of 120 miles per hour, what is the terminal velocity of the 3-inch mouse? (unit is mph)(c)…arrow_forwardAn object of mass 125 kg is released from rest from a boat into the water and allowed to sink. While gravity is pulling the 1 object down, a buoyancy force of 40 times the weight of the object is pushing the object up (weight = mg). If we assume that water resistance exerts a force on the object that is proportional to the velocity of the object, with proportionality constant 20 N-sec/m, find the equation of motion of the object. After how many seconds will the velocity of the object be 50 m/sec? Assume that the acceleration due to gravity is 9.81 m/sec². Find the equation of motion of the object. x(t) =arrow_forward
- After completing your physics class, you are hired to help design a cigar lounge in a nightclub. The ventilation system is critical to this design, as it must circulate all the air in the room every 25 min to filter and purify it, respecting national health regulations. The ventilation ducts you will use have a square cross-section. If the lounge has a volume of 186 m3, and the fans pushing the air give you an airspeed of 3 m/s inside the ducts, what must be the minimum length of one side of the square duct? Assume that air can be treated as an incompressible fluidarrow_forwardA balloon filled with helium gas has an average density of ρb = 0.39 kg/m3. The density of the air is ρa = 1.23 kg/m3. The volume of the balloon is Vb = 0.045 m3. The balloon floats upward with acceleration a. a.) Express the acceleration of the balloon a in terms of the variables given in the problem statement, assuming upwards is the positive direction. b.) Calculate the numerical value of a in m/s2.arrow_forwardA balloon filled with helium gas has an average density of ρb = 0.31 kg/m3. The density of the air is about ρa = 1.23 kg/m3. The volume of the balloon is Vb = 0.075 m3. The balloon is floating upward with acceleration a. Calculate the numerical value of F in N.arrow_forward
- After completing your physics class, you are hired to help design a cigar lounge in a nightclub. The ventilation system is critical to this design, as it must circulate all the air in the room every 27 min to filter and purify it, respecting national health regulations. The ventilation ducts you will use have a square cross-section. If the lounge has a volume of 184 m3, and the fans pushing the air give you an airspeed of 3.9 m/s inside the ducts, what must be the minimum length of one side of the square duct? Assume that air can be treated as an incompressible fluid. Give your answer in metresarrow_forwardConsider an airplane with a total wing surface of 100 square meters (m2). At a certain speed the difference in the air pressure below and above the wings is 5% of atmospheric pressure. What is the lift force on the airplane in units of kN (kilo Newtons)? kN Use 100 m2 100 kPa for the atmospheric pressure. %3Darrow_forwardSuppose that a thin metal wire in the shape of a semicircle occupies the curve C, where C is the top half of the circle x² + y² = 16. The mass density of the wire is described by the function p(x, y) = x³y. Find the total mass of the wire.arrow_forward
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