Final answer:
The average speed of the dog running across the yard can be calculated by dividing the distance traveled by the time taken. For the given measurements of 30 meters in 0.70 s, the average speed is 42.86 m/s.
Step-by-step explanation:
1. The equation for the dog's average horizontal speed is:
Average speed = distance traveled / time taken
2. To calculate the average speed of the dog traveling 30 meters in 0.70 s:
- Average speed = 30 meters / 0.70 s
- Average speed = 42.86 m/s
3. Rounded to the nearest hundredth, the average speed is 42.86 m/s.