# Multiple choice questions-mechanics and heat/thermodynamics

Question 1 : At t=0, a wheel rotating about a fixed axis at a constant angular acceleration has an angular velocity of 2 rad/s. Two seconds later it has turned 5 complete revolutions. What is the angular acceleration of this wheel?

multiple choice:

a : 17 rad/s^2

b : 14 rad/s^2

c: 20 rad/s^2

d: 23 rad/s^2

Question 2 : A particle moves according to the equation x=10t^2, where x is in meters and t is in seconds. Find the average velocity for the time interval from 2.0 second to 2.1 second.

a: 41 M/s

b: 100m/s

Question 3 : If A=(12i-16j) and B=(-24i+10j), what is the magnitude of the vector C=(2A-B)?

a: 42

b: 22

c: 64

d: 90

Question 4 : Steam at 100 degrees C is added to ice at 0 degree C. The mass of the steam is 10.0g and the mass of the ice is 50.0g. What is the final temperature of the mixture?

a: 20.4 Deg. C

b: 40.4 Deg. C

c: 80.8 Dec C

d: 90.1 Deg. C

Question 5 : A body oscillates with simple harmonic motion along the x-axis. Its deplacement varies with time according to the equation x=5 sin (PIE + PIE/3). The velocity (in m/s) of the body at t=1 second is:

a: +8

b: -8

c: -14

d: +14

Question 6 : The speed of a 4.0 kg object is given by v=(2t)m/s, where t is in seconds. At what rate is the resultant force on this object doing work at t=1 second?

a: 48W

b: 40w

c: 56W

d: 16W

Question 7 : A house has well-insulated walls. It contains a volume of 100m^3 of air at 300K. Calculate the energy required to increase the temperature of this diatomic gas by 2 degrees Cel. Assume it is heating at constant pressure and use Cp=7r/2.

a: 118kJ

b: 236kJ

c: 354kJ

d: 472K

Question 8 : A 9.00kg hanging weight is connected to a string over a pulley to a 5.00kg block that is sliding on a flat table. If the coefficient of kinectic friction is 0.15, find the tension in the string.

a: 28.3N

b: 36.2N

c: 40.4N

d: 53.4N

Question 9 : A car of mass 1000kg moves with a speed of 50 m/s on a circular track of radius 100m. What is the magnitude of its angular momentum (in kg m^2/s) relative to the center of the racetrack?

a: 5 x 10^2

b: 5 x 10^6

c: 2.5 x 10^6

d: 2.5 x 10^4

Question 10 : A 3-kg particle has velocity of (3i-4j) m/s. Find the magnitude of its momentum.

a: 9kg m/s

b: -12 kg m/s

c: 15 kg m/s

d: 3 kg m/s

Question 11 : The exhaust temperature of a Carnot heat engine is 350 degree C. What is the intake temperature if the efficiency is 25.0%?

a: 400 deg. C

b: 543 deg. C

c: 558 deg. C

d: 830 deg. C

Question 12 : A sinusoidal wave is described by y=(0.30 m)sin(0.20x-40t). Determine the wave speed.

a: 100m/s

b: 133 m/s

c: 150 m/s

d: 200 m/s