Which one is the answer

Use the empirical rule. the mean speed of a sample of vehicles along a stretch of highway is 70 miles per hour, with a standard deviation of 4 miles per hour. estimate the percent of vehicles whose speeds are between 66 miles per hour and 74 miles per hour. (assume the data set has a bell-shaped distribution.)

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

What properties of a moving object are used in determining the object's energy of motion