An airplane flying directly eastward at a constant speed travels 303 km in 2.0 h. (a) What is the average velocity of the plane?
 km/h

(b) What is its instantaneous velocity?
 km/h

A spaceship hovering over the surface of Venus drops an object from a height of 69 m. How much longer does it take to reach the surface than if dropped from the same height on Earth? Neglect air resistance in both cases. [The acceleration due to gravity on Venus is 90.7% of that on Earth, gVenus = (0.907)g.]
s

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?