Calculate work done by expanding gas of 1 mole if initial pressure is 4000 Pa, initial volume is 0.2 m3. Assume a two processes: (1) isobaric expansion to 0.3 m3 (2) isothermal expansion to 0.3 m3. 1. Isobaric expansion: Also: A 50% increase in temperature!

2. Isothermal expansion: Also: A ~67% decrease in pressure!

An infinitely long wire, as shown in the figure, is uniformly charged with density of λ. The radius of the ¼ circle is R. Find the electric field at O. O B A ∞ y A ∞ θ θ x B∞ AB

Contribution from filled part: A uniformly charged sphere (charge density of ρ) with a sphere hole inside is shown in the figure. Find the electric field intensity at the center of the hole. Filled: O r d Contribution from filled part:

Two point charges (q and -2q) are located at x=1m and x=-1m, respectively. Another point charge is located on the X axis. What is the position of this charge so that the net electric force on it is zero?

Find the magnetic field intensity at P. r =0.1 cm 30o 30o P

An electron is passing A with a speed of 104 m/s in a perpendicular magnetic field. Find the radius of the electron’s circular motion and the frequency of the cyclotron. frequency

A straight long wire with current I is placed beside a metallic trapezoid . ab=bc=ad=L. Distance between point d and the wire is l. The trapezoid freely falls a height H from still. Find 1) the instant induced current in the trapezoid when it falls H. 2) the potential difference between dc at that moment. 60o

A setup of double-slit interference is shown below. D=1. 2m, d=0. 45mm A setup of double-slit interference is shown below. D=1.2m, d=0.45mm. If the distance between adjacent bright lines on the screen is 1.5mm. Find the wavelength of the source light. P D △x

asin =2(l /2) the width of central maximum In experiment of Fraunhofer diffraction from a single slit, f = 0.5m，=5000Å，the width of the slit a=0.1mm. Find the width of central maximum asin =2(l /2) the width of central maximum

A space craft with a proper length of L0=90m moves at v=0 A space craft with a proper length of L0=90m moves at v=0.8c with respect to one observer. Measured by the observer, What is the time interval between the craft’s head and end passing through the observer? △t1 = L/v =2.25×10-7 s