Arace car is traveling around a track under what circumstance would you hear the highest pitch

The velocity of car is 80.0 miles per hour. what is the velocity of car in meters per second? (1 km -0.621 miles) m/s

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

The seven sisters, seven stars located more than 400 light-years away in the taurus constellation can be seen here with venus and another constellation, orion. the seven stars stay grouped together but seem to move, like the planet venus. why do stars seem to move like planets in the night sky?