a cyclist goes 25m/s on her first journey and it takes her 50 seconds to finish that part. on her second journey she covers 900m distance. her average speed is 18m/s. calculate her speed in the second part of the journey. SOMEONE PLEASE HELP AND EXPLAIN. EXPLAIN IT TO ME

A900 kg roller coaster car is travelling westward on the track and begins to slow down from 18m/s to 2m/s. how long does it take the roller coaster car to decelerate if the force acting on the car to slow it is 7024n? how far does the roller coaster travel during this time?

What is the internal energy of 4.00 mol of diatomic nitrogen gas n2 at 455k

Density of salty water as compared to the density of pure water is(a) is less(b) is always equal(c) is always more(d) may be less or more