A physics book has a height of 26 cm, a width 21 cm, and a thickness of 3.5 cm. a. What is the density of the physics book if it weighs 19 N?

b. Find the pressure that the physics book exerts on a desktop when the book lies face up.

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.

(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?