Please help! A wooden block slides down a ramp that is 16 meters long in 4 seconds. What was the average speed of the wooden block?
A. 16 m/s
B. 20 m/s
C. 64 m/s
D. 4 m/s

The magnetic field inside a superconducting solenoid is 4.50 t. the solenoid has an inner diameter of 6.20 cm and a length of 26.0 cm. determine (a) the magnetic energy density in the field and (b) the energy stored in the magnetic field within the solenoid.