Un electrón que se mueve paralelamente al eje de las abscisas con una velocidad de v Ԧ
= 105 m/si

Ԧ, entra

perpendicularmente a un campo magnético uniforme B = −0, 2 T k
a) Dibuja la fuerza que ejercerá el campo magnético sobre el electrón.
b) Calcula el módulo de la fuerza que actúa sobre el electrón.

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?