A concave mirror is designed so that a person 20.0 cm in front of the mirror sees an upright image magnified by a factor of
two. What is the radius of curvature of this mirror?
{26.67 cm}

Afixed electric space heater wired by a cable with an ampacity of 30 a should draw a maximum current of a. 30 a. b. 24 a. c. 15 a. d. 27 a.

An ideal polarizer with its transmission axis rotated 30 degrees to the vertical is placed in a beam of unpolarized light of intensity 10w/m^2. after passing through the polarizer, what is the intensity of the beam? a. 8.7 w/m^2 b. 7.5 w/m^2 c. 5.0 w/m^2 d. 10 w/m^2 e. 2.5 w/m^2

Suppose a wire with a current is pushed upward by a magnetic field. how would the wire move if the direction of the current reversed? explain your answer.