1. The problem statement, all variables and given/known data What takes more energy? Accelerating a car from 10-20m/s or from 20-30m/s? Why? 2. Relevant equations 3. The attempt at a solution Since KE = 1/2mv^2, I suppose the higher the velocity is the more kinetic energy the car will have, but I have no clue how to solve this problem.
Won't the bigger change in kinetic energy require the greater energy? You know that conservation of energy thing? Plug in the numbers.
so is this right? since m is constant it is just 1kg 1/2mv^{2} 1/2(1kg)(10m/s)^{2} = 50 joules 1/2(1kg)(20m/s)^{2} = 200 joules 1/2(1kg)(30m/s)^{2} = 450 joules KE for (10-20m/s) = 150 joules KE for (20-30m/s) = 250 joules So accelerating from 20-30m/s requires 100 more joules of energy?