Answer:
Force and displacement.
Explanation:
Work done is positive when we push table and it move in the direction of applied force.
Seismic wave is the answer
Average speed = total distance / time ⇒ total distance = average speed * time
Average speed = 270 km / p hours
distance = d
hours = x
d = 270/p * x
It would be "Researchers found environmental safe replacements for CFC's"
