A pontoon boat travels across a lake in a straight line and increases in speed uniformly from vi = 18.5 m/s to vf = 36.0 m/s in a displacement Δx of 250 m. We wish to find the time interval required for the boat to move through this displacement. g (a) Draw a coordinate system for this situation.

(b) What

analysis model is most appropriate for describing this situation?

(c) From the analysis model, what equation is most

appropriate for finding the acceleration of the speedboat?

(d) Solve the equation selected in part (c) symbolically for

the boat’s acceleration in terms of vi , vf , and ?x. (e) Substitute

numerical values to obtain the acceleration numerically.

(f) Find the time interval mentioned above.

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

In the united states, tornadoes generally occur because of the freezing of ocean water underwater earthquakes meeting of cool and warm air masses shifting of warm and cool ocean currents

Which is an advantage of subdividing science into different areas?