In projectile motion the horizontal component of the velocity at the top of the trajectory is
A. non-zero, and less than the initial horizontal component of the velocity.
B. non-zero, and equal to the initial horizontal component of the velocity
C. zero
D. non-zero, and greater than the initial horizontal component of the velocity
B. non-zero, and equal to the initial horizontal component of the velocity
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A barge is 10.0 m wide and 60.0 m long and has vertical sides. The bottom of the hull is 1.20 m below the water surface. What is the weight of the barge and its cargo, if it is floating in fresh water?
A) 3.53 MN B) 6.39 MN C) 6.82 MN D) 7.06 MN E) 9.54 MN
Four of the five answers listed below are characteristics of water. Select the exception
a. Water stabilizes temperature. b. Water is an excellent solvent. c. Water has cohesion and surface tension. d. Water produces salts. e. Water is less dense when solid.
Two long concentric horizontal aluminum tubes of 0.2 m and 0.25 m diameter are maintained at 300 K and 400 K respectively. The space between the tubes is filled with nitrogen. If the surfaces of the tubes are polished to prevent radiation, estimate the rate of heat transfer for gas pressure of (a) 1 MPa and (b) 10 kPa in the annulus.
? Two concentric horizontal aluminum tubes with nitrogen between them
? Diameters ? Di = 0.2 m
? Do = 0.25 m
? Temperatures ? Ti = 300 K
? To = 400 K
? Surface of tubes is polished
FIND
The rate of heat transfer for
(a) Pressure (pa) = 1 MPa
(b) Pressure (pb) = 10 kPa
ASSUMPTIONS
? Steady state conditions
? Radiative heat transfer is negligible
? Only the density of the nitrogen is affected by the pressure
PROPERTIES AND CONSTANTS
From Appendix 2, Table 33, for Nitrogen at one atmosphere and the mean temperature of 350 K
Correcting the density for Pressure
A ball is falling toward the ground. Which of the following statements are false?
a) The force that the ball exerts on the Earth is equal in magnitude to the force that the Earth exerts on the ball. b) The ball undergoes the same acceleration as Earth. c) The magnitude of the force the Earth exerts on the ball is greater than the magnitude of the force the ball exerts on the Earth.
1. Statements a and b are false. 2. Statements a, b, and c are all false. 3. Statements a and c are false. 4. Statements b and c are false.