What force takes away some of the cars' total mechanical energy during the roller coaster ride?

An experiment is designed to test the relationship between the initial height of a basketball before it is dropped to the height of its rebound bounce. the height of the rebound bounce is measured using a scale positioned behind the ball. in the above experiment, which condition would not be controlled? a). the starting height of the ballb). the surface the ball bounces on c). the type of ball d). the method to measure the rebound height of the ball

There are weak or strong attractive forces between atoms of liquids with a high viscosity

Which one of the following research methods can show cause and effect