Un niñno empuja una caja al aplicarle una fuerza horizontal de 8 N. Una fuerza de friccion cinetica actua sobre la caja con una magnitud de 5 N cuando ´esta es arrastrada 0.7 m por el piso, ¿cuales son (a) el trabajo realizado por la fuerza aplicada por el niño y (b) el aumento en energıa termica de la caja y el piso?

Apositive charge moves in the direction of an electric field. which of the following statements are true? check all that apply. check all that apply. 1.the potential energy associated with the charge decreases. 2. the electric field does positive work on the charge. 3. the electric field does negative work on the charge. 4. the potential energy associated with the charge increases. 5. the electric field does not do any work on the charge. 6. the amount of work done on the charge cannot be determined without additional information.