You are testing a new roller coaster ride in which a car of mass m moves around a vertical circle of radius r. in one test, the car starts at the bottom of the circle (point a) with initial kinetic energy ki. when the car reaches the top of the circle (point b), its kinetic energy is ki/4, and its gravitational potential energy has increased by ki/2. what was the speed of the car at point a, in terms of g and r?

Cin carbonh in hydrogeno in oxygen

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.