# Search results

1. ### Heat Transfer - finding rate of heat transfer

Homework Statement A 0.8m high and 1.5m wide double pane window consisting of two 3mm thick layers of glass(k=0.78W/mK) is separated by a 10mm wide stagnant air space(k=0.026 W/mK). The convection heat transfer coefficients on the inner and outer surfaces of the window are 10W/m^2K and 35W/m^2K...
2. ### Charged particles moved into a B-field

Homework Statement Two radioactive isotopes of singly charged plutonium(Pu-249 and Pu-244) are accelerated through a potential difference of 3.00kW and enter a uniform magnetic field of 1.50T directed perpendicular to their velocities. By performing relevat calculations, show that the ratio of...
3. ### Two long wires carrying current

Homework Statement Two long wires carrying current I1 and I2 in opposite directions pass through a closed path S as shown in the picture. What are the values of ∫B⋅ds and ∫E⋅ds if: i) I1=I2=1A ii) I1=1A and I2=0A? Homework Equations Ampere's Law: ∫B⋅ds=μ0I Faraday's Law: ∫E⋅ds=-dΦB/dt The...
4. ### Circular motion

Homework Statement A small ball of mass 0.50 kg is attached to a cord and perform uniform-speed circular motion of radius 2.0 m in a vertical plane. i) If the speed of the circular motion is 10m/s, determine the tension in the cord at the lowest point of the circular motion. ii)...
5. ### 1D motion

Homework Statement The position s (in metres) of a particle, as a function of time t (in seconds), is described by the equation s=5i+4r^2j. i and j are perpendicular unit vectors. a) Calculate the position of the particle at t=5. b) Determine the particle's average velocity between t=0 and...
6. ### Constrcutive interference

Homework Statement One speaker is located at the origin and the other is located at (x,y)=(0,3.00m). The speakers emit identical sound waves of wavelength 2.00m which are initially in phase. Where does constructive interference occur? ANS: x=1.50m The Attempt at a Solution...
7. ### Electric Potential & Electric Field

Homework Statement Three positive charges lie on the x-axis; q1 = 15 μC is at the origin, q2 = -30 μC is at x = 2 m, and q3 = 15 μC is a x = 3 m. ( please also refer to the attachment.) Find the electric potential and electric field at point “P” aroused from q1, q2 and q3. The Attempt at...
8. ### Wave- displacement for a point

Homework Statement A wave on a string has a wave function with the form of: y(x,t)=0.02sin(6.35x+2.63t) Find the shortest time for the displacement of the string at any point on the chain changes from 0.01m to -0.02m. The Attempt at a Solution The answer said we can set x=0. And...
9. ### R and I of DC circuit

Homework Statement http://postimg.org/image/8oweasluj/ Each rectangle in the figures represents a resistor with resistance=2.9kΩ. a) What is the net resistance of the circuit of Fig 1 connected to the battery? Each resistance has R=2.9 kΩ. b) What is the current flowing into the...
10. ### Thermal, steady-flow, table, continuity

Homework Statement Steam at 2 MPa and 208°C enters a nozzle with 20m/s. During the expansion process, its enthalpy drops to 2.86 MJ/kg because of the losses encountered. a) Determine the exit velocity from the nozzle. b) If the mass flow rate is 1kg/s, determine the flow area at the...