Question

At midnight, the depth of snow on a road is 6 cm. The snow falls at a steady rate and the depth increases by 2 cm per hour until 4 am, when it stops. At 10 am the snow starts to melt, so the depth decreases at a constant rate and by 3 pm, the road is clear.

A graph of the depth of snow (in cm) against time since midnight is shown below. The horizontal scale is marked in hours using the 12 hour clock.

Choose the TWO correct options about this graph from the following list.

Select one or more:

The intercept on the horizontal axis represents the depth of snow at midnight.

Between 10 am and 3 pm, the gradient of the line is about −2.8 cm h^-1.

The maximum depth of snow was 15 cm.

From midnight to 4 am, the gradient of the line is 6 cm h^-1.

Between the times of 10 am and 3 pm, the gradient of the line is positive.

The line is horizontal between the times of 4 am and 10 am.

The gradient of the line between midnight and 4 am represents the time when the snow started to fall.

Answer 1