Physics Answers

A BODY HAS A MASS OF 15KG AND IT IS BEING PUSHED HORIZONTALLY WITH A FORCE OF 100N IF IT HAS A COEFFICIENT OF KINETIC FRICTION 0.3 THEN WHAT IS THE ACCELERATION OF THE BODY)

The energy stored per unit volume of the inductor is called the energy density of the magnetic field. Why?

A force of 1,200 N is exerted on the small piston of a hydraulic press. The area of the small piston is 24 cm2 while the area of the larger piston is 360 cm2. What force will the larger piston sustain?

What can you conclude about the reliability of the human sense of touch for comparing temperature?

How does the strength of the magnetic field that is 1 cm from a current-carrying 

       wire compare with the strength of the magnetic field that is 4 cm from the wire?

At what distance a long, straight wire carrying a current of 3 A can develop a

        magnetic field of 7x10-7 T

 Find the current in a long, straight wire needed to develop a magnetic field of    

       5x10-7 T at 6m from the wire.

Find the magnetic field at a distance 3m from a long, straight wire carrying a

      current of 2 A.

A woman weighing 75 kg stands on a spring scale in elevator. During the first 3 seconds of motion from rest, the tension T in the hoisting cable is 8300 N. The total mass of the elevator , woman scale is 750 kg.

1.Find the vertical acceleration of the elevator.

2.Find the reading R of the scale in Newtons during this interval.

3.Find the upward velocity of the elevator at the end of a 3 seconds.

A solid copper sphere has a net positive charge. The charge is distributed uniformly over the surface of the sphere, and the electric field inside the sphere is zero. Then a negative point charge outside the sphere is brought close to the surface of the sphere. Is all the net charge on the sphere still on its surface? If so, is this charge still distributed uniformly over the surface? If it is not uniform, how is it distributed? Is the electric field inside the sphere still zero? In each case justify your answers.