Answer:
7.54 in
Explanation:
The motor's shaft rotates at 20 rpm. The 30 tooth gear is attached to the motor, so it also rotates at 20 rpm.
The 150 tooth gear meshes with the 30 tooth gear. Its rotational speed is:
20 rpm × (30 / 150) = 4 rpm
The wheel is attached to the 150 tooth gear, so it also rotates at 4 rpm. The radius of the wheel is half a foot or 6 inches. So the linear speed of the robot is:
4 rpm × (2π rad / rev) × (1 min / 60 s) × 6 in = 2.51 in/s
In 3 seconds, the robot moves a distance of:
2.51 in/s × 3 s = 7.54 in
Round as needed.
