A photographer uses his camera, whose lens has a 50 mm focal length, to focus on an object 3.5 m away. He then wants to take a picture of an object that is 30 cm away. In which direction must the lens move to focus on this second object? How far must the lens move to focus on this second object?

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

Agraduated cylinder contains 63.0 ml of water. a piece of gold, which has a density of 19.3 g/ cm3, is added to the water and the volume goes up to 64.5 ml. calculate the mass in grams of the gold that was added to the water. explain how you got your answer.

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?