Problem 10 the projector in kimpel 102 is about 7m = 700cm from the screen at the front of the classroom. from the size of the projector enclosure, the object in the projector cannot be more than 5cm from the projector lens. what is the approximate focal length of the lens in the projector? select one of the following: 3 (a) 4.96cm (b) 5.04cm (c) 30.3cm (d) 350cm (e) 700cm

Answer;

hot magma rises and pushes up toward the lithosphere, and as it cools it cycles back down toward the core to be heated again.

explanation; convection currents are the circular pathways taken by a fluid that enhances heat transfer by the process known as convection which occurs in fluids.convection currents transfer heat from one place to another by mass motion of a fluid. earth mantle is in a semi-liquid state and behaves like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from heat of the earth's core, as the rock loses heat into the earth's crust it becomes cooler and more dense, then sinking back down to the core, then repeating the cycle.

Yup your right can give me more detail  

Same the answer is b