A roller coaster with a mass of 20kg sits at the top of a 30 m high hill. What is the Potential energy of the roller coaster? (Formula: PE=mgh)
(g= 9.8m/s)

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg