Field Theory Answers

You slide a 325N trunk up a 20.0° inclined plane with a constant velocity by exerting a force of 211N up, parallel to the inclined plane.

What is the component of the trunk’s weight parallel to the plane?

What is the sum of your applied force, friction and the parallel component of the trunk’s weight?  Why?

What is the size and direction of the frictional force?

What is the coefficient of friction?

A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 18m/s.  The cliff is 50.m above a flat horizontal beach.  

How long after being released does the stone strike the beach below the cliff?  

With what velocity does it land?

A golfer wants to drive a golf ball a distance of 310yards (283m).  If the 4-wood launches the ball at 21° above the horizontal, what must the initial speed of the ball be in order to achieve the required distance?

A toroidal sample of magnetic material of susceptibility x = 2 × 10^-2 is wound with 100 turns of wire carrying a current of 2 A. The toroid is 0.10 m long.

(a) Find the solenoidal current density.(2)

(b) Determine the magnetic field intensity H produced by the current.(2)

(c) Calculate μ, the magnetic permeability of the material.(2)

(d) Calculate the induced magnetization M in the material.(2)

(e) Calculate the magnetic field B resulting from the current and the magnetization of the

material

Considering the radius of the Earth as 6400 m and the horizontal component of the Earth’s magneticfield at the equator as0.4× 10^-4 Wb m^-2, with what minimum momentum could an electron encircle the Earth at the equator? (charge of electron = 1.6 × 10^-1C) 

 (a)How do you shield a given region from any external electrostatic field? Explain briefly.

(b) Determine a unit vector perpendicular to the plane of the two forces 𝐴⃗= 𝚤̂+2 𝚥̂+ 3𝑘^

and B-> =5𝚤̂+10𝚥̂+ 2𝑘^

1. (a) The electric field in a particular region is given by 𝐸= 5x𝚤̂+ 3y𝚥̂+ 2𝑘. Calculate the charge density inthat region 

B) The distance between two very small water droplets in a thunder cloud is 1 mm. One droplet carriesa charge of 2𝑒- and the other a charge of 𝑒􏰥. Determine the force between the twodroplets(Electron charge = 1.602176634×10−19 C)

A car travelling at a uniform speed of 120kmh passes two stations in 4mins, calculate the distance between the two stations

Electric field and electric potential at a point 3cm away from a point charge is E and V respectively. What is the electric field and electric potential at 9 cm away from the same charge.

If the velocity profile of a fluid over a flat plate is parabolic with free stream velocity of 120 cm/s occurring at 20 cm from the plate. Find the velocity gradient and shear stress at a distance of 10 cm from plate. dynamic viscosity = 8.5 Poise