The brakes in a car work because of
a. Archimedes' principle
b. Pascal's principle
c. Bernoulli's principle
d. Torricelli's principle
e. none of these principles
B
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Addition by 1. Components: Displacement vector src="https://sciemce.com/media/4/ppg__cp1pbb0313192044__f15g1q11g5.jpg" style="vertical-align: -5.0px;" />.(c) Determine the x and y components of vector 
is 75 cm long and points at 30° above the +x-axis. Displacement vector 
is 25 cm long and points along the -x-axis. Displacement vector 
is 40 cm long and points at 45° below the -x-axis.(a) Determine the x and y components of vector 
.(b) Determine the x and y components of vector 
.(d) Determine the x and y components of the resultant of these three vectors.(e) Determine the magnitude and direction of the resultant of these three vectors.
What will be an ideal response?
A solution with a boiling point of 82°C boils on the outside of a 2.5 cm tube with a No. 14 BWG gauge wall. On the inside of the tube flows saturated steam at 40 kPa(abs). The convection heat transfer coefficients are 8.5 kW/(m2 K) on the steam side and 6.2 kW/(m2 K) on the exterior surface. Calculate the increase in the rate of heat transfer if a copper tube is used instead of a steel tube
GIVEN
• Tube with saturated steam on the inside and solution boiling at 82°C outside
• Tube specification: 1 in. No. 14 BWG gauge wall
• Saturated steam in the pipe is at 40 kPa(abs)
• Convective heat transfer coefficients
? Steam side ( ci h ) : 8.5 kW/(m2 K)
? Exterior surface ( co h ) : 6.2 kW/(m2 K)
FIND
• The increase in the rate of heat transfer for a copper over a steel tube
ASSUMPTIONS
• The system is in steady state
• Constant thermal conductivities
SKETCH
The intake manifold of an automobile engine can be approximated as a 4-cm-ID tube, 30 cm in length. Air at a bulk temperature of 20°C enters the manifold at a flow rate of 0.01 kg/s. The manifold is a heavy aluminum casting and is at a uniform temperature of 40°C. Determine the temperature of the air at the end of the manifold.
GIVEN
• Air flow through a tube
• Tube inside diameter (D) = 4 cm = 0.04 m
• Tube length (L) = 30 cm = 0.30 m
• Inlet bulk temperature (Tb,in) = 20°C
• Air flow rate (m ) = 0.01 kg/s
• Tube surface temperature (Ts) = 40°C
FIND
• Outlet bulk temperature (Tb,out)
ASSUMPTIONS
• Steady state
• Constant and uniform tube surface temperature
SKETCH
PROPERTIES AND CONSTANTS
for dry air at the inlet bulk temperature of 20°C
Thermal conductivity (k) = 0.0251 W/(m K)
Absolute viscosity (?) = 18,240 × 10–6 (Ns)/m2
Prandtl number (Pr) = 0.71
Specific heat (c) = 1012 J/(kg K)
What is the average kinetic energy of a nitrogen molecule in the air in a room in which the air temperature is 17°C?
A) 6.01 × 10-21 J B) 4.00 × 10-21 J C) 5.00 × 10-21 J D) 7.00 × 10-21 J E) 9.00 × 10-21 J