7. Helen cycles for 20 minutes at 5m/s and then for a further 10 minutes at 4m/s (a) How far does she cycle altogether? (b) Draw a distance-time graph for her ride

## Step 1: Calculate the distance Helen cycles at 5 m/sThe distance Helen cycles at 5 m/s can be calculated using the formula for distance, which is speed multiplied by time. Given that Helen cycles at 5 m/s for 20 minutes, we first need to convert the time from minutes to seconds (since the speed is given in m/s). There are 60 seconds in a minute, so 20 minutes is 1200 seconds.### ## Step 2: Calculate the distance Helen cycles at 4 m/sSimilarly, the distance Helen cycles at 4 m/s can be calculated using the same formula. Given that Helen cycles at 4 m/s for 10 minutes, we first need to convert the time from minutes to seconds. 10 minutes is 600 seconds.### ## Step 3: Calculate the total distance Helen cyclesThe total distance Helen cycles is the sum of the distances she cycles at 5 m/s and 4 m/s.### ## Step 4: Draw a distance-time graph for her rideThe distance-time graph for Helen's ride would be a piecewise linear graph with two segments. The first segment would be a line from (0,0) to (20,6000), representing the first 20 minutes of her ride at 5 m/s. The second segment would be a line from (20,6000) to (30,8400), representing the next 10 minutes of her ride at 4 m/s.