Un malabarista act´ua en un recinto cuyo techo est´a 3 m arriba del nivel de sus manos. Lanza una pelota hacia arriba de modo que apenas llega al techo. Calcule:

a) ¿Qu´e velocidad inicial tiene la pelota?
Ahora bien, en el instante en que la primera pelota llega al techo, el malabarista lanza una segunda pelota hacia arriba
con una velocidad inicial de 6 m/s.
c) Cuando han transcurrido 0.4 s desde el lanzamiento de la segunda pelota, ¿a que altura sobre el punto de lanzamiento est´an ambas pelotas?
d) ¿A qu´e altura sobre el punto de lanzamiento se cruzan las dos pelotas?

b) ¿Cu´anto tiempo tarda la pelota en llegar al techo?

Thomas his older brothers, who own a junk yard, on the weekends to earn extra money. he likes to them push broken-down cars to the back of the junk yard because it makes him feel strong. last saturday, they pushed three cars with different weights, and he noticed he used different amounts of force for each one. the cars were the following weights: white car: 2,700 kg red car: 1,500 kg blue car: 2,100 kg think about how much force is needed to move each car. which correctly lists the cars in order from the most to least amount of force needed to move them? a) white, blue, red b) blue, red, white c) red, white, blue d) white, red, blue

Which of these is not a possible type of energy transformation? a. electrical energy into light energy b. sound energy into nuclear energy c. potential energy into kinetic energy d. kinetic energy into mechanical energy

Which is special about a dc circuit ? a. it has both series and parallel components b. it has only series or only parallel components c. charge moves in a single direction d. charge moves back and forth quickly