A speed-time graph shows that a car moves at 10 m/s for 10 s. The car’s speed then steadily decreases until it comes to a stop at 30 s. Which of the following describes the slope of the speed-time graph from 10 s to 30 s?
Alinear, horizontal
Bcurved, upward
Clinear, sloping downward
Dlinear, sloping upward
Alinear, horizontal
Bcurved, upward
Clinear, sloping downward
Dlinear, sloping upward