A ball of mass is thrown straight upward and reaches a maximum height above the…
PHYSICS · Single correct · CBSE · Physics · Work and Energy · Work and Energy
Problem
A ball of mass m is thrown straight upward and reaches a maximum height h above the launch point. Student A chooses the launch point as the zero of gravitational potential energy, while Student B chooses the maximum height as zero. Which statement best describes how their results compare?
(a) Student B calculates a larger decrease in gravitational potential energy and therefore predicts a larger speed for the ball when it returns to the launch point.
(b) Both students obtain identical potential-energy values and identical return speeds because the zero level must be the same for all observers.
(c) They obtain different numerical values for potential energy at the top, but they calculate the same speed of the ball when it returns to the launch point.
(d) Student A calculates a smaller gravitational potential energy at every point and therefore predicts a smaller return speed for the ball.