Final answer:
Convert the number of revolutions per second to radians per second. Hence, the angular speed of the lawn roller is 7.54 radians per second.
Step-by-step explanation:
The angular speed of the lawn roller can be calculated by converting the number of revolutions per second to radians per second. Since there are 2π radians in one revolution, we can multiply the number of revolutions per second by 2π to find the angular speed in radians per second.
Given that the lawn roller makes 1.2 revolutions per second and has a diameter of 30 inches, we can calculate the radius by dividing the diameter by 2. The radius is 15 inches or 0.381 meters.
Therefore, the angular speed of the roller is (1.2 revolutions/s) * (2π radians/revolution) = 7.54 radians/second.