Question

A cruise ship with a mass of 1.00×107kg strikes a pier at a speed of 0.750 m/s. It comes to rest 6.00 m later, damaging the ship, the pier, and the tugboat captain’s finances. Calculate the average force exerted on the pier using the concept of impulse. (Hint: First calculate the time it took to bring the ship to rest.)

Answer 1

Answer: The required force = 4.7 x 105 N

Explanation:

Mass of the ship m = 1.00 x 107 Kg

Initial speed u = 0.750 m/s

Final speed v = 0 m/s

Average speed s =( 0.750 + 0) / 2 = 0.375 m/s

Time taken to bring the ship to rest t = $\frac{distance}{speed}$    

= $\frac{6}{0.375}$

= 16 s

Average force exerted on the pier F =$\frac{m(v - u )}{t}$

F  = $\frac{1.00 x 107 ( 0 - 0.750 )}{16}$

F  = - 4.7 x 105 N

Hence the required force = 4.7 x 105 N