Thermodynamis of air in a basketball

  • Thread starter Thread starter amiv4
  • Start date Start date
  • Tags Tags
    Air Basketball
AI Thread Summary
The discussion centers on a physics problem involving the thermodynamics of air in a basketball during compression. The basketball's air, initially at 20.0°C and 2.00 atm, is compressed to 80% of its volume, resulting in a maximum temperature of 47.4°C. The change in internal energy (ΔU) is calculated using the formula ΔU=nC_vΔT, with C_v given as 20.76. An attempt to solve for ΔU resulted in a value of 0.00333657, which was deemed incorrect, leading to a reevaluation using the first law of thermodynamics, where Q=0 and ΔU is equal to -W. The work done on the ball is expressed as W=nC_v(T_1-T_2), indicating the need for accurate calculations of n and temperature changes to determine the correct internal energy change.
amiv4
Messages
24
Reaction score
0

Homework Statement


A player bounces a basketball on the floor, compressing it to 80.0 % of its original volume. The air (assume it is essentially N_2 gas) inside the ball is originally at a temperature of 20.0 C and a pressure of 2.00 atm. The ball's diameter is 23.9 cm

Temperature at maximum compression equals 47.4 C

By how much does the internal energy of the air change between the ball's original state and its maximum compression?
\DeltaU=?

Homework Equations



\DeltaU=nC_v\DeltaT
C_v=20.76

The Attempt at a Solution



n=.0000058657

\DeltaU=.00333657
but that's not right
 
Physics news on Phys.org


Start with the first law

Q-W=ΔU

now no heat is being added to the system so Q=0

You're left with ΔU= -W. What is the work done on the ball?
 


W=nC_v(T_1-T_2)
that is the same thing i was using
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

When to use C(subv) and C(subp) for Q heat equation
Replies
2
Views
3K
Calculating Work Done on a Basketball Dropped from 5m
Replies
1
Views
1K
Momentum of golf ball and basketball
Replies
9
Views
7K
Adiabatic compressed air and energy calculations
2
Replies
60
Views
7K
Thermodynamics Cycle: Gas Temperature and Work Calculation | Homework Solution
Replies
1
Views
1K
The Bouncing Ball: Understanding Energy Conservation
Replies
4
Views
2K
Spherical bubble rises to surface, Ideal Gas, Thermal Energy
Replies
5
Views
4K
Finding Maximum Height of a Projectile
Replies
9
Views
4K
Increase in Internal Energy of a gas during compression
Replies
10
Views
6K
Absolute Temperature and the Ideal Gas Law
Replies
1
Views
5K

Hot Threads

Recent Insights

Back
Top