PHY 221–001
Triton College
Spring 2012
Practice Final
Twenty-five questions
Useful formulas:
Constant acceleration: vx = v0x + axtvx2 = v0x2 + 2ax(x – x0)
Relative motion:
Ffriction = µFnormalw = mgg = 9.80 m/s2
W = FsFspring = –kx
Ugrav = mgyWgrav = –Ugrav
K1 + Ugrav, 1 + Uelastic, 1 + Wother = K2 + Ugrav, 2 + Uelastic, 2
For a closed system:
PHY 221–001
Triton College
Spring 2012
Practice Final
Elastic collisions:Ktot, 1 = Ktot, 21-D elastic collisions: vA1 – vB1 = vB2 – vA2
Constant angular acceleration:
s = rv = r
IP = ICM + Md2
Torque:
Rolling without slipping:vcm = R
For constant torque: W = zP = zz
L = IPrecession:
Rotational Equilibrium:
G = 6.673 × 10–11 Nm2/kg2Circular orbits:
Elliptical orbit: Spherical shell:
Apparent weight: Schwarzschild radius:
PHY 221–001
Triton College
Spring 2012
Practice Final
Simple harmonic motion:
x(t) = Acos(t + )
vx,max = A
Angular SHM: = cos(t + )Simple pendulum:
Physical pendulum:
Damped oscillation:
Underdamped: where:
Critically damped: Overdamped: where s1, s2 < 0
pabs = pgauge + patm
L = L0TV = V0T = 3Q = mcT = nCTC = Mc
Q = mLHnet = Ae (T4 – Ts4)
Ideal gases: pV = nRTpV = NkTm = nMVan der Waals:
Monatomic gas: Diatomic gas: Monatomic solid: CV = 3R
Maxwell-Boltzmann:
PHY 221–001
Triton College
Spring 2012
Practice Final
dW = pdVU = Q – WdU = dQ – dWdU = nCVdTCp = CV + R
Adiabatic process, ideal gas:
TK = TC + 273.151 cal = 4.186 J1 Btu = 1055 J
Water:Lf = 3.34 × 105 J/kgLv = 2.256 × 106 J/kg
NA = 6.022 × 1023 molecules/mol
Heat engines: Otto cycle:
Refrigerators: Carnot cycle:
Carnot heat engine: Carnot refrigerator:
Reversible process: Microscopic:
Conversion factors:100 cm = 1 m1 km = 1000 m1 m = 109 nm1 g/cm3 = 1000 kg/m3
1 m3 = 1000 L = 106 cm31 Pa = 1 N/m2
1 atm = 1.013×105 Pa = 1.013 bar = 14.70 lb/in21 psia = 1 lb/in2 absolute1 psig = 1 lb/in2 gauge
2 rad = 360° rad = 180°The Sun: mS = 1.99 × 1030 kg
The Earth: mE = 5.97 × 1024 kgRE = 6.38 × 106 mrE = 1.50 × 1011 m
The speed of light: c 299792458 m/s
PHY 221–001
Triton College
Spring 2012
Practice Final
1) The position of a certain particle as a function of time is given as: x(t) = 1.00t2 – 4.00t + 5.00, where x is in meters and t is in seconds. Is the particle's speed increasing or decreasing at t = 1.00 s?
2) For the situation described in problem 1, what is the particle's average acceleration in the time interval from t = 1.00 s to t = 2.00 s?
3) An electron is experiencing uniform circular motion (constant speed) due to a constant magnetic field. The radius of its circular path is 10.0 mm. Calculations indicate that its speed is 1.00 × 109 cm/s. What is the electron’s acceleration?
4) A factory worker pushes a 40.0 kg crate across the horizontal factory floor, at a constant velocity, with a constant horizontal force of 65.0 N. What is the coefficient of kinetic friction, k, between the crate and the floor?
PHY 221–001
Triton College
Spring 2012
Practice Final
5) Given that the mass of and electron is 9.11 × 10–31 kg, what is the magnitude of the force acting on the electron of problem 3?
6) The factory worker in problem 4 pushes the crate 15.0 m. How much work was done on the crate by the worker, how much by friction, how much overall?
7) An object initially at rest experiences a constant net force (same magnitude and direction) of 250.0 N. What is its kinetic energy after it has traveled 40.0 m?
PHY 221–001
Triton College
Spring 2012
Practice Final
8) A spring with a spring constant of k = 400.0 N/m is mounted horizontally, and is compressed 2.00 cm from its equilibrium position. If it is then stretched to 4.00 cm beyond its equilibrium position, what would be the change in the energy stored in the spring?
9) A ball of mass 0.40 kg moves horizontally at a velocity of 30.0 m/s. It bounces off of a wall and it has a velocity of 26.0 m/s in the opposite direction immediately after the collision. If the ball was in contact with the wall for 0.012 s, what was the average force exerted on the ball by the wall?
10) On a frictionless horizontal track, two gliders move toward each other. Glider A has an initial velocity of vA1 = +0.300 m/s and mass mA = 0.250 kg. Glider B has mass mB = 0.500 kg, and an initial velocity of
vB1 = –0.100 m/s. What is their (signed) velocity after they collide and stick together?
PHY 221–001
Triton College
Spring 2012
Practice Final
11) A uniform meter stick is 1.000 m long, and its mass is m = 0.150 kg. Taking it to be a thin rod, its moment of inertia about an axis through its center of mass is ICM = 0.0125 kg m2. What is its moment of inertia about a parallel axis going through its 75.0 cm mark?
12) A force of 8.00 N is applied tangentially to a drum of radius 5.00 cm. Measurements indicate that its angular acceleration is = 20.0 rad/s. What is the moment of inertia for the drum?
13) A uniform meterstick of mass 150.0 g is balanced motionless by a support point at its 60.0 cm mark. A 75.0 g weight is providing the counterbalance. Where on the meterstick is the weight placed?
PHY 221–001
Triton College
Spring 2012
Practice Final
14) Given that the mass of Neptune is 17.2 times that of Earth, and that its radius is 3.81 times that of Earth, how much would a person weigh on Neptune if that person weighs 850 N on Earth?
15) A satellite is to have a circular orbit around the Earth with a period of T = 12.0 hours. What should its altitude be? (RE = 6.38 × 106 m)
16) A glider of mass 0.400 kg is attached to springs on a frictionless horizontal track. After a slight tap, the glider moves back and forth with a period of T = 2.75 s. What is the effective spring constant of the springs?
PHY 221–001
Triton College
Spring 2012
Practice Final
17) If a damping force where added to the setup in problem 16 of the form F = –bvx, what value of b would give critical damping?
18) Sea water has a density of sw = 1.03 × 103 kg/m3, and lead has a density of Pb = 1.14 × 104 kg/m3. While lifting a large lead block that is submerged under sea water, a force of 8915 N is used. What is the mass of the lead block?
19) Water comes into a house through a pipe of diameter d = 2.00 cm at a pressure of 44.1 psig. A 1.00cm diameter pipe takes the water to a bathroom 5.00 m above. If the only water flow is through a faucet in the bathroom, and the incoming flow rate is 0.471L/s: a) What is the flow rate out of the bathroom faucet? b)What is the gauge pressure of the water coming out of the faucet?
PHY 221–001
Triton College
Spring 2012
Practice Final
20) A 200.0 g sample of ice starts at a temperature of –5.00 °C, and is placed in an insulated beaker containing 1,000.0g of water at 70.0°C. What is the final temperature of the water after the ice melts? The specific heat of ice is 2090 J/kg∙K, and the specific heat for water is 4186 J/kg∙K.
21) A copper bar of length L = 100.0cm and cross-sectional area A = 6.00cm2 connects a hot water tank of constant temperature T = 80 °C to another tank of cold water at T= 10 °C. At equillibrium, what is the heat current through the bar? Ignore heat loss from the bars to the air. (kCu = 385.0 W/m∙K)
22) A constant-volume container has a volume of 1.50 L (0.00150 m3), and it contains an ideal gas whose pressure is atmospheric pressure (1.013×105 Pa), and whose temperature is 0°C. A very carefully performed experiment determines that 27.83 J of energy is required to raise the gas's temperature to 20°C. a) How many moles of molecules are in the container b) Is the gas monatomic, diatomic, or something else?
PHY 221–001
Triton College
Spring 2012
Practice Final
23) A cyclic thermodynamic process, A→B→C→D→A occurs in isobaric and isochoric stages in an ideal gas, so that its pressure and volume have the given values. How much work does the gas do per cycle?
A: (2.5×105 Pa, 0.0010 m3), B: (2.5×105 Pa, 0.0030 m3),
C: (4.0×104 Pa, 0.0030 m3), D: (4.0×104 Pa, 0.0010 m3).
24) The gas in problem 21 is compressed adiabatically from state C to state A. Is the gas monatomic, diatomic or something else?
25) A Carnot refrigerator in a 295 K room has an internal temperature of 275 K. a) What is its coefficient of performance? b) If it is using 0.50 W of electrical power, at what rate is heat being removed from the inside?
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