Which of the following is an example of a force? a. electrons moving toward a positive charge b. a child kicking a soccer ball c. air pushing against a falling object d. all of the above

Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?

A17,250 kg rocket is pushed with a thrust of 6,450,284 n. what is the acceleration of the rocket?

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?