Water flows through a pipe that gradually descends from a height of 6.78 m to the ground. near the top, the cross-sectional area is 0.4 m^2, and the pipe gradually widens so that its area near the ground is 0.8 m^2. water leaves the pipe at a speed of 16.8 m/s. what is the difference in the water pressure between the top and bottom of the pipe?

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Curious carl calculated the density of a cube to be 4.50 g/cm3. what is the density of the cube in g/l?

What would be the result of an alpha particle coming into a magnetic field? a) the alpha particle will stop moving. b) the alpha particle will reverse its direction. c) the alpha particle will be deflected in a curve path. d) the alpha particle will continue to travel in a straight line.