A linear plot of speed versus elapsed time has a slope of 5.0 m/s2 and a vertical intercept of 5.0 m/s. (a) What is the change in speed in the time interval between 4.0 seconds and 6.0 seconds? The answer is 10, which completely makes sense to me. But.... (b) What is the speed when the elapsed time is equal to 5.0 seconds? 5.0 m/s2 after 5 seconds, i thought the speed would be 25 (speed starts at 0)? I'm not sure where the vertical intercept comes in.