Imagine that you are helping your little sister construct a scale model of the Universe for her 1st Grade science project. Being incredibly imaginative, you decide to use a bright yellow Wilson tennis ball as the Sun. The radius of the tennis ball
is exactly 3.0 cm. When you look up the radius of the real Sun, you find it to have a radius of 7.0 x 10^8 meters.
1) This information will allow you to find the scale factor for your model Universe. Show the complete calculation
of the scale factor here:
scale factor = meter in the model Universe =
meter in the real Universe

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?