1. Christmas tree lights need a transformer to convert the 240 V AC to 12 V AC. If there are 50 turns on the 12 V secondary coil, how many turns are there in the primary coil? a. 100 b. 240 c. 600 d. 1000 e. 12000

A 47-kg pole vaulter running at 11 m/s vaults over the bar. Her speed when she is above the bar is 1.2 m/s. Neglect air resistance, as well as any energy absorbed by the pole, and determine her altitude as she crosses the bar.

A 56-kg pole vaulter running at 10 m/s vaults over the bar. Her speed when she is above the bar is 1.3 m/s. Neglect air resistance, as well as any energy absorbed by the pole, and determine her altitude as she crosses the bar.

Hi there, quick true or false question. If you double the mass of an object that is at some elevated position, above a reference level, youd double it's gravitational potential energy. True or False Thanks!!