A space probe approaches a planet, taking measurements as it ...

[Alygatorr01285]

A space probe approaches a planet, taking measurements as it goes. If it detects a potential difference of 6000 MV between the altitudes of 253,000 km and 276,000 km above the planet's surface,
 
  what is the approximate electric field strength produced by the planet at 264,500 km above the surface? Assume the electric field strength is approximately constant at these altitudes.
  A) 561 N/C B) 0.261 N/C C) 261 N/C D) 493 N/C

Question 2

Light passes through three ideal polarizing sheets. Unpolarized light enters the first sheet and the resultant vertically polarized beam continues through the second sheet and third sheet.
 
  The second sheet has its transmission axis at 50 with respect to the first sheet, and the third sheet is at 70 with respect to the first sheet.
  (a) What percent of the original intensity emerges from filter 1?
  (b) What percent of the original intensity emerges from filter 2?
  (c) What percent of the original intensity emerges from filter 3?

[Sierray]

Answer to Question 1

C

Answer to Question 2

(a) 50 (b) 21 (c) 18