Ill give brainlest please help

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.

Using gravity, an elephant can pull a mouse towards it from the ground. true or false explain why. will give brainliest if answered fast and the best explanation