Physics Answers

what happens to the (1) resistance and (2) current flow through a conductor if:

b. conductivity increases

c. decrease in temperature

2 pts) A light wave is initially polarized in the +y direction and has intensity 1.0 W/m^2. It encounters a polarizer whose axis is 60 degrees counterclockwise from the +x axis. After the wave has emerged from the polarizer, i.

In which direction does its electric field point?

A. +x

B. +y

C. +z

D. 30° counterclockwise from +x

E. 60° counterclockwise from +x

ii. What is its intensity?

A. 0.25 W/m2

B. 0.50 W/m2

C. 0.75 W/m2

D. 0.87 W/m2

E. 1.0 W/m2

A uniform 3.0 kg disk of radius 30 cm is rotating around its central axis at an angular speed of 72 rad/s. At time t = 0, a man begins to slow it at a uniform rate until it stops at t = 20 s. (a) Find its angular acceleration. (b) By time t- 10 s, how much work had the man done? (c) For full 20 s, at what average rate did the man do work?

A spherical ball has a radius of 0.2 m and electric charge is 20uc in its center.Calculate the electric flux pass through the spherical ball.

A copper wire has a resistance of 15.0 at a temperature of 14 degrees * C . After a current passes through the windings, the resistance rose to 22.5 ohms. To what temperature was the wire heated?

A wall with a thermal conductivity of 0.50W/m·K is maintained at 40.0°C. The heat

transfer through the wall is 250.0W. The wall surface area is 1.50m2 and its thickness is 1.00cm.

Determine the temperature at the other surface.

Two small spheres spaced apart have equal charge. How many electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57 x 10^-21 N?

A 5 kg object is located at a distance of 9.0 x109 km from the center of a larger object whose mass is 2.0 x 1030 kg.

a. What is the size of the force acting on the smaller object

b. What is the size of the force acting on the larger object?

c. What is the acceleration of the smaller object when it is released?

d. What is the acceleration of the larger object when it is released?

A person is holding a 5.0 kg mass in one hand as shown in the figure above.

You can ignore the mass of the forearm itself.What is the force exerted by the bicep in order to keep the arm horizontal?(in N to 2s.f)

1. two charged spheres q1 = 2.00x10^11 C; and q2=-5.00x^-8C are held fixed at positions 0.0500m apart. Calculate the magnitude of each electrostatic force between two spheres
2. Determine the electric flux of an electric field E = 2000 N/C with an area of 10m^2 and 45 degree angle
3. compute for the amount of charge (q) that passes through a conductor in 10 seconds with the amount of current equal to 20 a.