You are taking a photo of a poster on the wall of your dorm room, so you can't back away any farther than 3.1 m to take the shot. the poster is 0.80 m wide and 1.2 m tall, and you want the image to fit in the 15-mm × 22-mm frame of the film in your camera. what is the longest focal length lens that will work? answer in cm with 2 significant figures.

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.