{21.24} A 3kg particle has a velocity of (3i-4j) m/s. Find the magnitude of its momentum?

A 3kg particle has a velocity of (3i-4j) m/s. Find the magnitude of its momentum? ============================================= Answers: a) 9kg m/s b) -12 kg m/s c) 15 kg m/s d) 3 kg m/s ################################################## A sinusoidal wave is described by y=(0.30m)sin(0.20x-40t). Determine the wave speed. =============================================== Answers: a) 100 m/s b) 133 m/s c) 150 m/s d) 200 m/s ================================================ OTA: Please take this problem only if you can show step by step problem solving techniques and equations used. Thank you. a) 100 m/s b)

{11.12}Steam at 100 degree C is added to ice at 0 degree C. The mass of the steam is 10.0kg and the mass of the ice is 50.0g. What is the final temperature of the mixture?The exhaust temperature of a Carnot heat engine is 350 degree C. What is the intake temperature if the efficiency is 25.0 percent?

Steam at 100 degree C is added to ice at 0 degree C. The mass of the steam is 10.0kg and the mass of the ice is 50.0g. What is the final temperature of the mixture? ================================================= Answers: a) 20.4 degree C b) 40.4 degree C c) 80.8 degree C d) 90.1 degree C ################################################### The exhaust temperature of a Carnot heat engine is 350 degree C. What is the intake temperature if the efficiency is 25.0 percent? ====================================== Answers: a) 400 degree C b) 543 degree C c) 558 degree C d) 830 degree C ========================================= OTA: please take this problem only if you can show... click for more

{23.4} A house has well-insulated walls. It contains a volume of 100 m^3 of air at 300 K. What is the necessary flow speed in the duct?

A house has well-insulated walls. It contains a volume of 100 m^3 of air at 300 K. Calculate the energy required to increase the temperature of this diatomic gas by 2 degree C. Assume it is heating of constant pressure and use Cp = 7R/2. ================================================= Answers: a) 118 kJ b) 236 kJ c) 354 kJ d) 472 kJ ################################################ A room measure 3.0m by 4.5m by 6.0m. The heating and air conditioning ducts to and from the room are circular with diameter 0.30m, and the air in the room is to be exchanged every 12 minutes. What is the necessary flow speed in the duct? (Assume that the density of the air is constant). =============... click for more

{25.18} How far is the speaker from each observer? The velocity (in m/s) of the body at t=1 second is:

A loudspeaker is placed between 2 observers who are 120m apart, along the line connecting them. If one observer records a sound level of 60.0 dB and the other records a sound level of 90 dB, how far is the speaker from each observer? Hint: use the equation which relates to the difference between the decibel levels to the distance from the source. ================================================ Answers: a) 3.7, 116.3 b) 4.3, 115.7 c) 6.2, 113.8 d) 8.6, 111.4 ################################################# A body oscillates with simple harmonic motion along the x-axis. Its displacement varies with time acording to the equation x=5sin(3.14t + 3.14/3). pi=3.14. The velocity (in m/s) o... click for more

{20.2} At what rate is the resultant force?Find the change in potential energy?

The speed of a 4.0kg object is given by (2t) m/s, where t is in seconds. At what rate is the resultant force on this object doing work at t = 1 second? ================================================= Answers: a) 48 W b) 40 W c) 56 W d) 16 W ################################################### A 10kg object is initially at the top of a rise, at point A. It then moves down to point B. Choose point B to be your zero level for gravitational potential energy. Find the change in potential energy of the object if point B is 10m lower than point A? ================================================ Answers: a) -980 b) -10 c) -100 d) -98 =================================================... click for more