The amount of charge flowing through a particular point in a conductor is represented by the equation Q = at^3 + bt + c, where a = 3.00 A/s^2, b = 5.00 A, and c = 8.00 A*s. Determine the current density at t = 0.700 s if the cross-sectional area of the conductor at the point of consideration is 2.50 cm^2. A/m^2

A100 kg running back runs at 5m/s into a stationary linebacker. it takes 0.5 for the running back to be completely stopped

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3