Distance at 40 Miles per Hour for 2 Hours

Step-by-step solution

1. Step 1: Identify the relationship

   For constant speed, distance = rate × time.

2. Step 2: Substitute

   r = 40 miles per hour, t = 2 hours.

   $$d=80$$

3. Step 3: Units

   Hours cancel in (miles/hour) × hours, leaving miles.

Why this works

Word problems become equations once you name the quantities. Constant-speed motion uses d = rt. If speed changed, you would split the trip into pieces or use average speed, which is not the same as averaging two speeds unless the times are equal.