Kinetic Theory - Online Test
Q1.
In constructing a large mobile, an artist hangs an aluminum sphere of mass 6.0 kg from a vertical steel wire 0.50 m long and 2.5 in cross-sectional area. On the bottom of the sphere he attaches a similar steel wire, from which he hangs a brass cube of mass 10.0 kg. Compute the tensile strain.
Answer : Option A
Explaination / Solution:
No Explaination.
Q2.
A tank used for filling helium balloons has a volume of 0.300 and contains 2.00 mol of helium gas at 20.0. Assuming that the helium behaves like an ideal gas, What is the average kinetic energy per molecule?
Answer : Option B
Explaination / Solution:
E=32kT=32×1.38×10−23×293=6.07×10−21J
Q3.
Air at 20.0 in the cylinder of a diesel engine is compressed from an initial pressure of 1.00 atm and volume of 800.0 to a volume of 60.0 . Assume that air behaves as an ideal gas with and that the compression is adiabatic. Find the final pressure of the air
Answer : Option A
Explaination / Solution:
P1V1γ=P2V2γP2=P1(V1V2)γ=1×(80060)1.4=37.6atm
Q4. Air at 20.0 in the cylinder of a diesel engine is compressed from an initial pressure of 1.00 atm and volume of 800.0 to a volume of 60.0 . Assume that air behaves as an ideal gas with and that the compression is adiabatic. Find the final temperature of the air
Answer : Option C
Explaination / Solution:
T1V1γ−1=T2V2γ−1T2=T1(V1V2)γ−1=1×(80060)1.4−1=826K
Q5. Nine particles have speeds of 5.00, 8.00, 12.0, 12.0, 12.0, 14.0, 14.0, 17.0, and 20.0 m/s. find the particles’ average speed.
Answer : Option C
Explaination / Solution:
vav=∑vn=5.0+8.0+12.0+12.0+12.0+14.0+14.0+17.0+20.09vav=12.7m/sec
Q6.
Nine particles have speeds of 5.00, 8.00, 12.0, 12.0, 12.0, 14.0, 14.0, 17.0, and 20.0 m/s. What is the rms speed?
Answer : Option C
Explaination / Solution:
no. of molecule per unit volume
mean free path
Q7. In a 30.0-s interval, 500 hailstones strike a glass window with an area of 0.600 at an angle of 45.0 to the window surface. Each hailstone has a mass of 5.00 g and a speed of 8.00 m/s. If the collisions are elastic, what are the average force and pressure on the window?
Answer : Option B
Explaination / Solution:
Q8. In a 30.0-s interval, 500 hailstones strike a glass window with an area of 0.600 at an angle of 45.0 to the window surface. Each hailstone has a mass of 5.00 g and a speed of 8.00 m/s. If the collisions are elastic, what is the pressure on the window?
Answer : Option A
Explaination / Solution:
P=FAF=500×ΔpΔt=500×2mvcos45∘Δt=500×2×5×10−3×8×130×1.41A=0.6m2P=500×2×5×10−3×8×130×1.41×0.6=1.57Pa
Q9. A 14.5 kg mass, fastened to the end of a steel wire of unstretched length 1.0 m, is whirled in a vertical circle with an angular velocity of 2 rev/s at the bottom of the circle. The cross-sectional area of the wire is 0.065 . Calculate the elongation of the wire when the mass is at the lowest point of its path.
Answer : Option D
Explaination / Solution:
No Explaination.
Q10. How many atoms of helium gas fill a balloon of diameter 30.0 cm at 20.0C and 1.00 atm?
Answer : Option D
Explaination / Solution:
PV=NkTN=PVkT=1.01×105×(43×3.14×(0.15)3)1.38×10−23×293=3.53×1023
