A book is sitting on a desk. What best describes the normal force acting on the book? the upward force the desk pushes on the book
the upward force the book pulls on the Earth
the downward force the book pushes on the desk
the downward force the Earth pulls on the book

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

Adiver named jacques observes a bubble of air rising from the bottom of a lake (where the absolute pressure is 3.50 atm) to the surface (where the pressure is 1.00 atm). the temperature at the bottom is 4.00 ∘c, and the temperature at the surface is 23.0 ∘c.what is the ratio of the volume of the bubble as it reaches the surface (vs) to its volume at the bottom (vb)? if jaques were to hold his breath the air in his lungs would be kept at a constant temperature. would it be safe for jacques to hold his breath while ascending from the bottom of the lake to the surface?