To solve this problem we will apply the first law of thermodynamics and we will make a balance between the heat transferred, its internal energy and the total work. Recall that for gases the definition of work can be expressed in terms of its pressure and volume. Let's start
Here,
dU = Internal Energy
dW = Work
But internal energy is unchanged, then
Where
= Change in Volume
P = Pressure
Finally, the expression of the heat transferred can be expressed in terms of pressure and volume, so it would end up becoming
Replacing,
Therefore the correct answer is B.
Answer:
20m/s
Explanation:
Given parameters:
Distance of throw = 50m
Time = 3s
Unknown:
Average speed = ?
Solution:
Average speed is distance divided by time;
Average speed = 
Insert the parameters and solve;
Average speed = 
= 16.66667m/s = 20m/s
Answer:
1.87 A
Explanation:
τ = mean time between collisions for electrons = 2.5 x 10⁻¹⁴ s
d = diameter of copper wire = 2 mm = 2 x 10⁻³ m
Area of cross-section of copper wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (2 x 10⁻³)²
A = 3.14 x 10⁻⁶ m²
E = magnitude of electric field = 0.01 V/m
e = magnitude of charge on electron = 1.6 x 10⁻¹⁹ C
m = mass of electron = 9.1 x 10⁻³¹ kg
n = number density of free electrons in copper = 8.47 x 10²² cm⁻³ = 8.47 x 10²⁸ m⁻³
= magnitude of current
magnitude of current is given as
= 1.87 A
80/60=
1.3333...........................................
