9. Which of the following has the greatest momentum?
O a. a 4.0 kg bowling ball moving at 2.0 m/s
O b. a 0.15 kg baseball moving at 10.0 m/s
c. a 1.6 x10^3 kg car moving at 0.5 m/s
O d. a 0.02 kg bullet moving at 950 m/s

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Chemical energy is a form of energy. a. heat b. kinetic c. potential d. electromagnetic

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.