A light plane travels a distance of 175m along a runway before takeoff. Find the work done by the plane engine if it is applying a force of 12500N.

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

You pump 25.0l of air at atmospheric pressure into a soccer ball that has a volume of 4.50l. what is the pressure inside the soccer ball if the temperature does not change?