# ### Differentiation

Q- At a sand and gravel plant, sand is falling off a conveyor and onto a conical pile at a rate of 10 cubic feet per minute.  The diameter of the base of the cone is 3 times the altitude.  At what rate is the height of the pile changing when the pile is 15 feet high?

### Magnetic Force

Q- A rectangular coil of wire, 22.0 cm by 35.0 cm and carrying a current 1.40 A, is oriented with the plane of its loop perpendicular to a uniform 1.50 T magnetic field in to the plane of the coil.

a) Calculate the net force and torque which the magnetic field exerts on the coil.

b) The coil is rotated through a 30.0º angle about the axis passing through center and parallel to smaller sides.  Calculate the net force and torque which the magnetic field exerts on the coil.

Solution:

### Refraction Through A Prism

Q- A horizontal beam of light that is incident on an equilateral prism. The base of the prism is horizontal. The prism (n = 1.40) is surrounded by a liquid whose index of refraction is 1.60. Determine the angle of emergence from the other surface, that is the exiting light makes with the normal to the right face of the prism. Solution:

### Sound and Vibration

Q- A heavy piece of hanging sculpture is suspended by a 90 cm long, 5.0 g steel wire. When the wind blows hard, the wire hums at its fundamental frequency of 80 Hz. What is the mass of the sculpture?

Solution:

### Mechanics: Conservation of momentum

Q- Two railroad cars moving on same track towards each other. One of mass 10000 kg with speed 0.3 m/s and the other of mass 15000 kg with speed of 0.1 m/s.

(a) What is the magnitude of their common velocity after they coule together?

(b) How much kinetic energy is lost during collision?

Solution:

## Do you have a problem?

You may request your problem to be added in question(s) of the day using contact page. It will be added as first come first serve and is free of charge.

You may contact to get customized homework help for your problems and assignments.