Una pelota de tenis de 100 g de masa lleva una rapidez de 20 m/s. Al ser golpeada por una raqueta, se mueve en sentido contrario con una rapidez de 40 m/s. Calcular el impulso. Si le pelota permanece en contacto con la raqueta 〖10〗^(-2) sg, ¿Cuál es el módulo de la fuerza media del golpe?

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?