A0.305 kg book rests at an angle against one side of a bookshelf. the magnitude and direction of the total force exerted on the book by the left side of the bookshelf are given by: fl= 1.52 nθl=31 degrees what must the magnitude and direction of the total force exerted on the book by the bottom of the bookshelf be in order for the book to remain in this position? fb= θb=

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?

Awave travels at a speed of 5.2 m/s. if the distance between crests is 0.40 m, what is the frequency of the wave? use f=v/wavelength a. 13 hz b. 2.1 hz c. 0.077 hz d. 5.6 hz

Explain why electric current cannot exist if a current doesn't have a voltage source.