Acceleration

A sports car and a school bus are stopped at a traffic light. When the light turns on green, they will both accelerate to start moving. A sports car is naturally able to speed very quickly but a school bus usually takes a little more pushing on the accelerator because it has more weight to pull from the back. The school bus will maintain a constant velocity while the sports car will probably speed up. Obviously when the light turns on green, the sports car and the school bus will have a postive acceleration. But when the light is going to turn red, they are going to have a negative accerleration. A school bus is mostly always carrying kids so the bus driver has to be very careful while hes driving so when he/she is about to stop at a red light, he/she might start slowing down a little before the light actually turns red. In contrast, the sports car might wait for the last minute to press on the brake to stop because it is a faster car and it can respond quickly.