If you increase the number of trials in an experiment it will make the test more valid and legitimate.As you take the same test/experiment once or twice you could see if your results are similar to each other.
Answer:
height = 45 m
Explanation:
Initial velocity = 0 m/s
Final velocity = 30 m/s
Acceleration due to gravity = +10m/s^2 ( because ball is going down )
Using the eqn of motion

where v= final velocity ; u = initial velocity ; g = acceleration due to gravity ; h = height
So,



Answer:
Speed
Explanation:
The distance traveled by an object in a unit of time is speed
Answer:
Most likely, it will be harder to get strong magnets to change phase because they have more density.