Chris and desiree are resting on an offshore raft after a swim. they estimate that 3.0 m separates the trough from the adjacent crest of each surface wave on the lake. they count 12 crests that pass by the raft in 20.0 s. how fast are the waves moving?
a. 1.2 m/s c. 2.3 m/s
b. 3.6 m/s d. 3.2 m/s

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong chain

Lacie kicks a football from ground level at a velocity of 13.9 m/s and at an angle of 25.0° to the ground. how long will the ball be in the air before it lands? how far will the football travel before it lands?

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?