A graph shows distance on the vertical axis and time on the horizontal axis. If the speed is steadily increasing, what will the line representing speed look like on the graph?

The distance will rise as time increases, at an increasng rate (slope). The curve is called an upward parabola.

a straigh diagonal line

It will be a straight line that has VERY STEEP SLOPE.

If the speed is steadily increasing, the line representing speed on the graph will be a straight line that starts from a lower point on the vertical axis (representing a lower initial speed) and gradually slopes upwards as it moves to the right along the horizontal axis (representing increasing time).

To understand why, it is helpful to remember that speed is the rate at which an object covers distance in a given amount of time. When the speed is steadily increasing, it means that for each unit of time that passes, the object is covering a greater distance compared to the previous unit of time. This can be represented by a line with a positive slope on the distance vs. time graph.

To graphically represent this line, you can plot pairs of values on the graph. For example, if at time t=0, the object is at distance d=0, you can start the line at the origin (0,0). Then, as the object covers more distance over time, you can plot additional points accordingly. As you connect these plotted points, you will observe a straight line with a positive slope, indicating the steadily increasing speed.