A certain LCD projector contains a single thin lens. An object 23.9 mm high is to be projected so that its image fills a screen 1.75 m high. The object-to-screen distance is 2.99 m. How far from the object should the lens of the projector be placed in order to form the image on the screen?

What’s #16 asking and how do i solve it?

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.

Abus travels 280km south along a straight path with an average velocity of 88km/h to the south. the bus stops for 24 min, then it travels 210 km south with an average velocity of 75 km/h to the south. how long does the total trip last?