As a train accelerates away from a station, it reaches a speed of 4.9 m/s in 5.1 s. If the train's acceleration remains constant, what is its speed after an additional 7.0s has elapsed?

Acceleration is the rate of change of the velocity of a moving object. To determine the speed the object has at a certain time, we need to determine the acceleration first by dividing the speed with the time given. We do as follows:

acceleration = 4.9 m/s / 5.1 s = 0.96 m/s^2

To determine the velocity after 7.1 s, we multiply 7.1 s to the acceleration.

speed or velocity = 0.96 x 7.1 = 6.52 m/s