Aperson throws a ball straight up in the air. the ball rises to a maximum height and then falls back down so that the person catches it. consider the ball while it is in the air. which of the following statements are true? just after the ball leaves the person's hand the direction of the acceleration is up. the acceleration is zero when the ball reaches its maximum height. the acceleration is about 9.8 m/s2 (down) when the ball is falling.

Very large accelerations can injure the body, especially if they last for a considerable length of time. one model used to gauge the likelihood of injury is the severity index ( ), defined as =/ . in the expression, is the duration of the accleration, but is not equal to the acceleration. rather, is a dimensionless constant that = the number of multiples of that the acceleration is equal to. in one set of studies of rear-end collisions, a person's velocity increases by 13.7 km/h with an acceleration of 36.0 m/s2 . let the + direction point in the direction the car is traveling. what is the severity index for the collision?

What would be the result of an alpha particle coming into a magnetic field? a) the alpha particle will stop moving. b) the alpha particle will reverse its direction. c) the alpha particle will be deflected in a curve path. d) the alpha particle will continue to travel in a straight line.

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?